diff --git a/backend/app/main.py b/backend/app/main.py
index 353edfe..0df4e4f 100644
--- a/backend/app/main.py
+++ b/backend/app/main.py
@@ -11,7 +11,7 @@ import os
 
 from app.config import settings
 from app.database import init_db
-from app.routers import photos, folders, heaps, tags, discard, library, search, auth, admin, sharing
+from app.routers import photos, folders, heaps, tags, discard, library, search, auth, admin, sharing, upload, download, features
 from app.services.scanner import start_initial_scan, bootstrap_default_source_root
 from app.services.cleanup import cleanup_data_integrity
 
@@ -95,6 +95,9 @@ app.include_router(tags.router, prefix="/api/v1/tags", tags=["tags"])
 app.include_router(discard.router, prefix="/api/v1/discard", tags=["discard"])
 app.include_router(library.router, prefix="/api/v1/library", tags=["library"])
 app.include_router(search.router, prefix="/api/v1/photos/search", tags=["search"])
+app.include_router(upload.router, prefix="/api/v1/upload", tags=["upload"])
+app.include_router(download.router, prefix="/api/v1/download", tags=["download"])
+app.include_router(features.router, prefix="/api/v1/features", tags=["features"])
 
 @app.get("/")
 async def root():
diff --git a/backend/app/routers/admin.py b/backend/app/routers/admin.py
index 27b04fc..1e756a0 100644
--- a/backend/app/routers/admin.py
+++ b/backend/app/routers/admin.py
@@ -18,6 +18,14 @@ from app.models.user import User
 from app.models.photos import Photo
 from app.models.folders import SourceRoot
 from app.config import settings
+from app.services.feature_flags import (
+    ALL_FLAGS,
+    snapshot as flags_snapshot,
+    set_flag,
+    reset_flag,
+    is_enabled,
+    FLAG_VISION_ENABLED,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -258,3 +266,141 @@ async def delete_user(
 
     logger.info(f"Admin '{admin.username}' deactivated user '{user.username}'")
     return {"status": "ok", "detail": f"User '{user.username}' deactivated"}
+
+
+# ---------------------------------------------------------------------------
+# AI / vision feature flags + manual triggers
+# ---------------------------------------------------------------------------
+
+class FeatureFlagUpdate(BaseModel):
+    """PATCH body for toggling a feature flag.
+
+    ``value`` sets an explicit override (true/false); omitting it clears
+    the override and reverts the flag to its YAML default.
+    """
+    value: Optional[bool] = None
+
+
+@router.get("/feature-flags")
+async def get_feature_flags(admin: User = Depends(require_admin)):
+    """Return every tunable feature flag with its current effective
+    value, YAML default, and whether an admin override is in effect."""
+    return {"flags": flags_snapshot()}
+
+
+@router.patch("/feature-flags/{flag_name}")
+async def update_feature_flag(
+    flag_name: str,
+    body: FeatureFlagUpdate,
+    admin: User = Depends(require_admin),
+):
+    """Set or clear an override for one flag. With ``value`` set, the
+    flag is pinned to that boolean; without it, the override is deleted
+    and the YAML default takes over again.
+
+    New value is observed by vision tasks on their next invocation —
+    there's no worker restart required.
+    """
+    if flag_name not in ALL_FLAGS:
+        raise HTTPException(status_code=404, detail=f"Unknown flag: {flag_name}")
+    try:
+        if body.value is None:
+            reset_flag(flag_name)
+            action = "cleared override"
+        else:
+            set_flag(flag_name, bool(body.value))
+            action = f"set to {body.value}"
+    except RuntimeError as e:
+        # Redis unreachable — surface as 503 so the UI doesn't think it
+        # succeeded silently.
+        raise HTTPException(status_code=503, detail=str(e))
+
+    logger.info(f"Admin '{admin.username}' {action} for flag '{flag_name}'")
+    return {"flags": flags_snapshot()}
+
+
+class BackfillVisionBody(BaseModel):
+    """POST body for triggering a vision backfill. ``task`` picks a
+    specific stage (``embed`` / ``ocr`` / ``detect`` / ``faces`` /
+    ``classify``); leaving it null runs every enabled stage. ``limit``
+    caps how many photos per stage are queued — useful for smoke-
+    testing a newly-enabled feature before committing a full run.
+    """
+    task: Optional[str] = None
+    limit: Optional[int] = None
+
+
+@router.post("/ai/backfill")
+async def trigger_ai_backfill(
+    body: BackfillVisionBody,
+    admin: User = Depends(require_admin),
+):
+    """Queue a vision backfill pass. Identical code path as the automatic
+    post-scan backfill — just triggered manually from the UI."""
+    if not is_enabled(FLAG_VISION_ENABLED):
+        raise HTTPException(
+            status_code=400,
+            detail="Vision is currently disabled; enable it before running a backfill.",
+        )
+    valid_tasks = {'embed', 'ocr', 'detect', 'faces', 'classify'}
+    if body.task is not None and body.task not in valid_tasks:
+        raise HTTPException(
+            status_code=400,
+            detail=f"task must be one of {sorted(valid_tasks)} or null",
+        )
+    if body.limit is not None and body.limit <= 0:
+        raise HTTPException(status_code=400, detail="limit must be positive")
+
+    # Import lazily so importing admin.py doesn't pull in the whole
+    # vision stack on startup (Celery task module loads numpy etc.).
+    from app.tasks.vision import backfill_vision
+
+    result = backfill_vision.apply_async(
+        kwargs={'task': body.task, 'limit': body.limit}
+    )
+    logger.info(
+        f"Admin '{admin.username}' queued vision backfill "
+        f"(task={body.task}, limit={body.limit}, celery_id={result.id})"
+    )
+    return {
+        "status": "queued",
+        "task_id": result.id,
+        "task": body.task,
+        "limit": body.limit,
+    }
+
+
+@router.post("/ai/recluster-faces")
+async def trigger_face_recluster(admin: User = Depends(require_admin)):
+    """Kick off face recluster. Normally auto-fires after a scan via a
+    debounced scheduler; this endpoint is for admins who want to force
+    a fresh clustering pass (e.g. after tweaking ``cluster_eps`` in
+    the YAML config)."""
+    if not is_enabled(FLAG_VISION_ENABLED):
+        raise HTTPException(
+            status_code=400,
+            detail="Vision is currently disabled; enable it before reclustering.",
+        )
+    from app.tasks.vision import recluster_faces
+
+    result = recluster_faces.apply_async()
+    logger.info(
+        f"Admin '{admin.username}' queued face recluster (celery_id={result.id})"
+    )
+    return {"status": "queued", "task_id": result.id}
+
+
+@router.post("/ai/rescan")
+async def trigger_full_rescan(admin: User = Depends(require_admin)):
+    """Dispatch the same scan_all_source_roots job the backend runs at
+    startup. Picks up any new files on disk and, through the
+    post-scan hook, queues a vision backfill for whatever still lacks
+    embeddings / OCR / etc.
+    """
+    from app.tasks.scan import scan_all_source_roots
+
+    result = scan_all_source_roots.apply_async()
+    logger.info(
+        f"Admin '{admin.username}' queued full rescan (celery_id={result.id})"
+    )
+    return {"status": "queued", "task_id": result.id}
diff --git a/backend/app/routers/download.py b/backend/app/routers/download.py
new file mode 100644
index 0000000..498305f
--- /dev/null
+++ b/backend/app/routers/download.py
@@ -0,0 +1,247 @@
+"""
+Download router — streams a .zip of every photo in a folder (recursively)
+or a heap back to the browser.
+
+Auth: both endpoints accept the regular Authorization header *or* a
+``?token=JWT`` query string, mirroring the media endpoints. That lets the
+frontend trigger a download with a plain ``<a href>`` (which can't set a
+header), keeping the client side a one-liner.
+
+Implementation: we build the zip into a ``NamedTemporaryFile`` and then
+stream its bytes back, deleting the temp file on the way out. Stored
+(uncompressed) mode because photos and videos are already compressed —
+deflating them again just burns CPU for a fraction of a percent. For
+very large libraries the temp-file route is mildly wasteful vs. a true
+streaming zip (zipstream-ng etc), but it avoids a new dependency and
+handles arbitrary folder sizes without blowing out RAM.
+"""
+import logging
+import os
+import re
+import tempfile
+import zipfile
+from typing import List
+
+from fastapi import APIRouter, Depends, HTTPException
+from fastapi.responses import StreamingResponse
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import get_current_user_media
+from app.models import Folder, Heap, Photo, SourceRoot
+from app.models.heaps import heap_photos
+from app.models.user import User
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter()
+
+
+def _safe_filename(name: str) -> str:
+    """Strip characters that Content-Disposition or Windows filesystems
+    would choke on. Keeps the download's filename readable without
+    needing any escaping on the client side."""
+    cleaned = re.sub(r'[\\/:*?"<>|\r\n\t]', '_', name).strip().strip('.')
+    return cleaned or 'download'
+
+
+async def _collect_folder_photos(
+    folder_id: str,
+    user: User,
+    db: AsyncSession,
+) -> tuple[str, str, List[Photo]]:
+    """Resolve a folder or source-root id → (base_path, display_name,
+    photos). ``base_path`` is the prefix we strip off each photo's
+    filepath when naming zip entries, so the archive mirrors the user's
+    on-disk structure under that folder.
+    """
+    folder = (await db.execute(
+        select(Folder).where(Folder.id == folder_id, Folder.user_id == user.id)
+    )).scalar_one_or_none()
+
+    base_path: str
+    display_name: str
+    if folder is not None:
+        base_path = os.path.normpath(folder.path)
+        display_name = folder.name or os.path.basename(base_path)
+    else:
+        sr = (await db.execute(
+            select(SourceRoot).where(
+                SourceRoot.id == folder_id,
+                SourceRoot.user_id == user.id,
+            )
+        )).scalar_one_or_none()
+        if sr is None:
+            raise HTTPException(status_code=404, detail="Folder not found")
+        base_path = os.path.normpath(sr.path)
+        display_name = sr.name or os.path.basename(base_path)
+
+    # Every photo whose filepath is at or below the base path — matches
+    # the same prefix convention folders.py uses for recursive deletes.
+    descendant_prefix = base_path.rstrip(os.sep) + os.sep
+    result = await db.execute(
+        select(Photo).where(
+            Photo.user_id == user.id,
+            Photo.is_discarded == False,  # noqa: E712
+            (Photo.filepath == base_path) | (Photo.filepath.like(descendant_prefix + '%')),
+        )
+    )
+    photos = list(result.scalars().all())
+    return base_path, display_name, photos
+
+
+def _build_zip(
+    photos: List[Photo],
+    arcname_fn,
+) -> tempfile.NamedTemporaryFile:
+    """Write ``photos`` into a fresh ZIP_STORED temp file.
+
+    ``arcname_fn(photo, used_names)`` returns the entry name to use for
+    the given photo; the caller supplies it because folder downloads
+    want path-preserving names while heap downloads flatten to bare
+    filenames (with a collision suffix).
+    """
+    tmp = tempfile.NamedTemporaryFile(delete=False, suffix='.zip')
+    try:
+        used: set[str] = set()
+        with zipfile.ZipFile(tmp, 'w', zipfile.ZIP_STORED, allowZip64=True) as zf:
+            for p in photos:
+                if not p.filepath or not os.path.exists(p.filepath):
+                    # Silent skip: the scanner may have indexed files
+                    # that have since been moved / unlinked by a shell.
+                    continue
+                name = arcname_fn(p, used)
+                used.add(name)
+                try:
+                    zf.write(p.filepath, name)
+                except OSError as e:
+                    logger.warning(f"Skipping {p.filepath} in zip: {e}")
+        tmp.close()
+        return tmp
+    except Exception:
+        tmp.close()
+        try:
+            os.unlink(tmp.name)
+        except OSError:
+            pass
+        raise
+
+
+def _stream_and_cleanup(path: str):
+    """Yield the temp zip in 1 MiB chunks and unlink it when the
+    iterator is exhausted (or GC'd, if the client disconnects early)."""
+    try:
+        with open(path, 'rb') as f:
+            while True:
+                chunk = f.read(1024 * 1024)
+                if not chunk:
+                    break
+                yield chunk
+    finally:
+        try:
+            os.unlink(path)
+        except OSError as e:
+            logger.debug(f"Temp zip cleanup failed for {path}: {e}")
+
+
+def _dedupe(name: str, used: set[str]) -> str:
+    """Return ``name`` (or ``name (2)``, ``name (3)`` ...) such that the
+    result doesn't collide with anything in ``used``. Needed for heap
+    downloads where two members can have identical filenames from
+    different folders."""
+    if name not in used:
+        return name
+    stem, ext = os.path.splitext(name)
+    n = 2
+    while True:
+        cand = f"{stem} ({n}){ext}"
+        if cand not in used:
+            return cand
+        n += 1
+
+
+@router.get("/folders/{folder_id}")
+async def download_folder(
+    folder_id: str,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user_media),
+):
+    """Zip every (non-discarded) photo under a folder/source-root and
+    stream it back. Entries preserve the folder structure relative to
+    the downloaded root so the resulting archive is a faithful snapshot.
+    """
+    base_path, display_name, photos = await _collect_folder_photos(
+        folder_id, current_user, db
+    )
+    if not photos:
+        raise HTTPException(status_code=404, detail="No photos to download")
+
+    def arcname(p: Photo, _used: set[str]) -> str:
+        # Relative path from the download root, falling back to the
+        # bare filename if the photo somehow lives outside base_path.
+        abs_path = os.path.normpath(p.filepath)
+        if abs_path.startswith(base_path + os.sep):
+            rel = abs_path[len(base_path) + 1:]
+        elif abs_path == base_path:
+            rel = os.path.basename(abs_path)
+        else:
+            rel = p.filename or os.path.basename(abs_path)
+        # Nest everything under display_name so users see one top-level
+        # folder inside the zip rather than loose files.
+        return os.path.join(_safe_filename(display_name), rel)
+
+    tmp = _build_zip(photos, arcname)
+    filename = _safe_filename(display_name) + '.zip'
+    return StreamingResponse(
+        _stream_and_cleanup(tmp.name),
+        media_type='application/zip',
+        headers={
+            'Content-Disposition': f'attachment; filename="{filename}"',
+            'Content-Length': str(os.path.getsize(tmp.name)),
+        },
+    )
+
+
+@router.get("/heaps/{heap_id}")
+async def download_heap(
+    heap_id: str,
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user_media),
+):
+    """Zip every photo in a heap. Heaps are flat collections, so entries
+    use the original filename (with a ``(2)`` collision suffix when
+    two members share a name)."""
+    heap = (await db.execute(
+        select(Heap).where(Heap.id == heap_id, Heap.user_id == current_user.id)
+    )).scalar_one_or_none()
+    if heap is None:
+        raise HTTPException(status_code=404, detail="Heap not found")
+
+    result = await db.execute(
+        select(Photo)
+        .join(heap_photos, heap_photos.c.photo_id == Photo.id)
+        .where(
+            heap_photos.c.heap_id == heap_id,
+            Photo.is_discarded == False,  # noqa: E712
+        )
+    )
+    photos = list(result.scalars().all())
+    if not photos:
+        raise HTTPException(status_code=404, detail="Heap is empty")
+
+    def arcname(p: Photo, used: set[str]) -> str:
+        bare = p.filename or os.path.basename(p.filepath or 'photo')
+        entry = os.path.join(_safe_filename(heap.name), _dedupe(bare, used))
+        return entry
+
+    tmp = _build_zip(photos, arcname)
+    filename = _safe_filename(heap.name) + '.zip'
+    return StreamingResponse(
+        _stream_and_cleanup(tmp.name),
+        media_type='application/zip',
+        headers={
+            'Content-Disposition': f'attachment; filename="{filename}"',
+            'Content-Length': str(os.path.getsize(tmp.name)),
+        },
+    )
diff --git a/backend/app/routers/features.py b/backend/app/routers/features.py
new file mode 100644
index 0000000..25b4c3e
--- /dev/null
+++ b/backend/app/routers/features.py
@@ -0,0 +1,23 @@
+"""
+Public feature-flag read API — lets the authenticated frontend know
+which AI-powered sections to render.
+
+This is NOT the admin mutation endpoint (that's in ``admin.py`` and
+gated by ``require_admin``). Here we only expose the effective boolean
+state so the UI can hide things like the People view, Tags view, or
+text-search affordances when the underlying pipeline stage is off.
+"""
+from fastapi import APIRouter, Depends
+
+from app.dependencies import get_current_user
+from app.models.user import User
+from app.services.feature_flags import ALL_FLAGS, is_enabled
+
+router = APIRouter()
+
+
+@router.get("")
+async def get_enabled_features(_: User = Depends(get_current_user)):
+    """Return ``{flag_name: bool}`` for every known flag, reflecting
+    the currently effective value (admin override or YAML default)."""
+    return {name: is_enabled(name) for name in ALL_FLAGS}
diff --git a/backend/app/routers/upload.py b/backend/app/routers/upload.py
new file mode 100644
index 0000000..c717817
--- /dev/null
+++ b/backend/app/routers/upload.py
@@ -0,0 +1,303 @@
+"""
+Upload router — lets users drop files (or whole folders) from their
+desktop into a destination Folder, preserving any sub-folder structure
+they bring with them.
+
+Each POST handles one file. The frontend fans out many parallel requests
+per drop, giving it per-file progress without the server having to
+invent a chunking protocol. For folder uploads, the browser passes
+`webkitRelativePath` under the `relative_path` field; any leading
+sub-directories there are materialised on disk (and as Folder rows)
+under the destination.
+
+Uploaded files are placed under the destination folder on the owner's
+media mount, indexed immediately (Photo row created), and queued for
+the same thumb + metadata pipeline that the scanner uses. An optional
+`heap_id` also drops them into a heap in the same request.
+"""
+import hashlib
+import logging
+import os
+from pathlib import Path
+from datetime import datetime
+from typing import Optional
+
+from fastapi import APIRouter, Depends, File, Form, HTTPException, UploadFile
+from sqlalchemy import insert, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.dependencies import get_current_user
+from app.models import Folder, Heap, Photo, SourceRoot
+from app.models.heaps import heap_photos
+from app.models.user import User
+from app.services.date_guess import has_date_warning
+from app.tasks.scan import SUPPORTED_EXTENSIONS, get_media_type
+from app.tasks.thumbs import generate_thumbnails
+from app.services.metadata import extract_metadata
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter()
+
+
+MAX_UPLOAD_BYTES = 500 * 1024 * 1024  # 500 MB per file cap.
+
+
+def _validate_segment(segment: str) -> str:
+    """Reject path segments that would escape the destination directory."""
+    segment = segment.strip()
+    if not segment or segment in ('.', '..') or '/' in segment or '\\' in segment:
+        raise HTTPException(status_code=400, detail=f"Invalid path segment: {segment!r}")
+    return segment
+
+
+def _sanitize_relative_path(rel: Optional[str]) -> list[str]:
+    """Split `relative_path` into safe segments (dirs + filename).
+
+    Empty or missing → []. Any absolute path, backslash, or `..` segment
+    raises 400 — we never want an upload to escape the destination.
+    """
+    if not rel:
+        return []
+    # Normalise backslashes to forward slashes; browsers on Windows send
+    # webkitRelativePath with forward slashes anyway, but defend in depth.
+    rel = rel.replace('\\', '/').strip('/')
+    if not rel:
+        return []
+    segs = [_validate_segment(s) for s in rel.split('/') if s]
+    return segs
+
+
+async def _resolve_destination(
+    folder_id: str,
+    user: User,
+    db: AsyncSession,
+) -> Folder:
+    """Resolve `folder_id` to a concrete Folder row the user owns.
+
+    Accepts both Folder ids and SourceRoot ids (for source roots, we
+    return the Folder row at the mount path — the scanner creates one
+    for every source root it walks). Raises 404 if neither matches.
+    """
+    folder = (await db.execute(
+        select(Folder).where(Folder.id == folder_id, Folder.user_id == user.id)
+    )).scalar_one_or_none()
+    if folder is not None:
+        return folder
+
+    sr = (await db.execute(
+        select(SourceRoot).where(SourceRoot.id == folder_id, SourceRoot.user_id == user.id)
+    )).scalar_one_or_none()
+    if sr is None:
+        raise HTTPException(status_code=404, detail="Destination folder not found")
+
+    root_folder = (await db.execute(
+        select(Folder).where(
+            Folder.source_root_id == sr.id,
+            Folder.user_id == user.id,
+            Folder.path == os.path.normpath(sr.path),
+        )
+    )).scalar_one_or_none()
+    if root_folder is None:
+        # First-time source root with no walk yet — create the row now so
+        # uploads work even before the initial scan has run.
+        root_folder = Folder(
+            name=sr.name or os.path.basename(sr.path),
+            path=os.path.normpath(sr.path),
+            source_root_id=sr.id,
+            user_id=user.id,
+        )
+        os.makedirs(root_folder.path, exist_ok=True)
+        db.add(root_folder)
+        await db.flush()
+    return root_folder
+
+
+async def _ensure_subfolder(
+    parent: Folder,
+    name: str,
+    user: User,
+    db: AsyncSession,
+) -> Folder:
+    """Return (or create) a Folder row named `name` under `parent`.
+
+    Also mkdirs the directory on disk. Idempotent — safe to call for a
+    path segment that already exists as a Folder row or directory.
+    """
+    child_path = os.path.normpath(os.path.join(parent.path, name))
+
+    existing = (await db.execute(
+        select(Folder).where(
+            Folder.path == child_path,
+            Folder.user_id == user.id,
+        )
+    )).scalar_one_or_none()
+    if existing is not None:
+        os.makedirs(child_path, exist_ok=True)
+        return existing
+
+    os.makedirs(child_path, exist_ok=True)
+    child = Folder(
+        name=name,
+        path=child_path,
+        parent_id=parent.id,
+        source_root_id=parent.source_root_id,
+        user_id=user.id,
+        is_hidden=parent.is_hidden,
+    )
+    db.add(child)
+    await db.flush()
+    return child
+
+
+def _unique_path(target_dir: str, filename: str) -> tuple[str, str]:
+    """Return a (filepath, filename) that doesn't collide with an
+    existing file on disk. Suffixes " (2)", " (3)", ... until a free
+    slot is found. Prevents upload-over-existing and keeps the user's
+    original file intact.
+    """
+    base, ext = os.path.splitext(filename)
+    candidate = os.path.join(target_dir, filename)
+    n = 2
+    while os.path.exists(candidate):
+        new_name = f"{base} ({n}){ext}"
+        candidate = os.path.join(target_dir, new_name)
+        n += 1
+    return candidate, os.path.basename(candidate)
+
+
+@router.post("")
+async def upload_file(
+    file: UploadFile = File(...),
+    destination_folder_id: str = Form(...),
+    relative_path: Optional[str] = Form(None),
+    heap_id: Optional[str] = Form(None),
+    db: AsyncSession = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+):
+    """Upload a single file into a destination folder (and optionally a
+    heap). For folder uploads, `relative_path` carries the sub-folder
+    chain from the browser's `webkitRelativePath`, and we materialise
+    it under the destination on disk + as Folder rows.
+
+    Returns the created photo's id on success. 4xx on unsupported file
+    type, bad path, missing destination, or too-large file.
+    """
+    # --- validate inputs -------------------------------------------------
+    raw_name = file.filename or ''
+    if not raw_name:
+        raise HTTPException(status_code=400, detail="Missing filename")
+
+    # Prefer the leaf of relative_path when present (it contains the
+    # original filename as the browser saw it inside the picked folder).
+    segs = _sanitize_relative_path(relative_path)
+    if segs:
+        leaf = segs[-1]
+        subdirs = segs[:-1]
+    else:
+        leaf = _validate_segment(os.path.basename(raw_name))
+        subdirs = []
+
+    ext = Path(leaf).suffix.lower()
+    if ext not in SUPPORTED_EXTENSIONS:
+        raise HTTPException(
+            status_code=400,
+            detail=f"Unsupported file type: {ext or '(none)'}",
+        )
+
+    dest_folder = await _resolve_destination(destination_folder_id, current_user, db)
+
+    target_folder = dest_folder
+    for seg in subdirs:
+        target_folder = await _ensure_subfolder(target_folder, seg, current_user, db)
+
+    target_dir = target_folder.path
+    os.makedirs(target_dir, exist_ok=True)
+    filepath, final_name = _unique_path(target_dir, leaf)
+
+    # --- stream to disk, hash as we go ----------------------------------
+    hasher = hashlib.sha256()
+    total = 0
+    try:
+        with open(filepath, 'wb') as out:
+            while True:
+                chunk = await file.read(1024 * 1024)
+                if not chunk:
+                    break
+                total += len(chunk)
+                if total > MAX_UPLOAD_BYTES:
+                    out.close()
+                    os.unlink(filepath)
+                    raise HTTPException(
+                        status_code=413,
+                        detail=f"File exceeds {MAX_UPLOAD_BYTES // (1024*1024)}MB limit",
+                    )
+                hasher.update(chunk)
+                out.write(chunk)
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error(f"Upload write failed for {filepath}: {e}")
+        if os.path.exists(filepath):
+            try:
+                os.unlink(filepath)
+            except OSError:
+                pass
+        raise HTTPException(status_code=500, detail=f"Upload failed: {e}")
+
+    file_hash = hasher.hexdigest()
+
+    # --- validate heap before committing the DB row ---------------------
+    if heap_id:
+        heap = (await db.execute(
+            select(Heap).where(Heap.id == heap_id, Heap.user_id == current_user.id)
+        )).scalar_one_or_none()
+        if heap is None:
+            # Destination heap vanished — still keep the file + photo row,
+            # but tell the caller so the UI can surface the mismatch.
+            heap_id = None
+
+    # --- create Photo row ------------------------------------------------
+    mtime_dt = datetime.fromtimestamp(os.stat(filepath).st_mtime)
+    photo = Photo(
+        filepath=filepath,
+        filename=final_name,
+        folder_id=target_folder.id,
+        user_id=current_user.id,
+        file_hash=file_hash,
+        media_type=get_media_type(filepath),
+        original_format=Path(filepath).suffix.upper()[1:],
+        file_size=total,
+        taken_at=mtime_dt,
+        taken_at_source='filesystem',
+        has_date_warning=has_date_warning(filepath, mtime_dt),
+        is_hidden=bool(target_folder.is_hidden),
+        processing_status='pending',
+    )
+    db.add(photo)
+    await db.flush()
+
+    if heap_id:
+        await db.execute(
+            insert(heap_photos),
+            [{"heap_id": heap_id, "photo_id": photo.id}],
+        )
+
+    await db.commit()
+
+    # Queue the same background work the scanner does so thumbnails +
+    # EXIF show up without the user having to trigger a rescan.
+    try:
+        generate_thumbnails.delay(photo.id)
+        extract_metadata.delay(photo.id)
+    except Exception as e:
+        logger.warning(f"Failed to queue post-upload tasks for {photo.id}: {e}")
+
+    return {
+        "photo_id": photo.id,
+        "filename": final_name,
+        "folder_id": target_folder.id,
+        "folder_path": target_folder.path,
+        "heap_id": heap_id,
+    }
diff --git a/backend/app/services/duplicates.py b/backend/app/services/duplicates.py
index 3f4ae13..50b2207 100644
--- a/backend/app/services/duplicates.py
+++ b/backend/app/services/duplicates.py
@@ -221,6 +221,13 @@ async def incremental_regroup(
             from datetime import timedelta
             since = datetime.now(timezone.utc) - timedelta(hours=1)
 
+        # Photo.added_at is stored as TIMESTAMP WITHOUT TIME ZONE, so
+        # asyncpg rejects aware datetimes with "can't subtract offset-naive
+        # and offset-aware". Normalise: if `since` has a tzinfo, convert
+        # it to UTC and drop the tzinfo so the bind parameter is naive.
+        if since.tzinfo is not None:
+            since = since.astimezone(timezone.utc).replace(tzinfo=None)
+
         # Get newly added photos (the "new" set).
         new_rows = (
             await session.execute(
@@ -349,6 +356,14 @@ async def _clip_neighbor_scan(
     for photo_id, vector in target_embeddings:
         # pgvector cosine distance: <=> operator
         # Find top 20 nearest neighbors within threshold.
+        # Serialize the vector as "[a,b,c,...]" — pgvector's text
+        # format uses commas; numpy's default str() joins with spaces
+        # which Postgres rejects with "invalid input syntax for vector".
+        if hasattr(vector, 'tolist'):
+            vec_seq = vector.tolist()
+        else:
+            vec_seq = list(vector)
+        vec_text = '[' + ','.join(f'{float(x):.8f}' for x in vec_seq) + ']'
         result = await session.execute(
             text("""
                 SELECT e.photo_id, (e.vector <=> :vec) AS distance
@@ -356,14 +371,14 @@ async def _clip_neighbor_scan(
                 JOIN photos p ON p.id = e.photo_id
                 WHERE e.model = :model
                   AND e.photo_id != :pid
-                  AND p.is_discarded = false
+                  AND p.is_trashed = false
                   AND p.is_hidden = false
                   AND (e.vector <=> :vec) < :threshold
                 ORDER BY e.vector <=> :vec
                 LIMIT 20
             """),
             {
-                'vec': str(vector),
+                'vec': vec_text,
                 'pid': photo_id,
                 'model': embedder_model,
                 'threshold': threshold,
diff --git a/backend/app/services/feature_flags.py b/backend/app/services/feature_flags.py
new file mode 100644
index 0000000..e630672
--- /dev/null
+++ b/backend/app/services/feature_flags.py
@@ -0,0 +1,301 @@
+"""
+Runtime feature flags for expensive pipeline stages.
+
+The YAML config (``mulita.yml``) ships reasonable defaults. Admins can
+toggle these at runtime from the Settings → AI Features tab without
+rebuilding the image or editing the bind-mounted YAML; the overrides
+live in Redis so both the FastAPI backend and the Celery workers see
+the same value within ~1s of the write.
+
+The key namespace is:
+
+    mulita:flags:<name>   → "true" | "false"
+
+An unset key means "fall back to the YAML default" — so an admin who
+has never touched the tab sees exactly the config-file behaviour.
+
+Only bool flags live here. Thresholds, batch sizes, model names etc.
+stay in the YAML file because flipping them safely requires restarting
+the vision workers (model reload, ONNX session re-init); that's not
+something a single admin click should do.
+"""
+from __future__ import annotations
+
+import logging
+from typing import Optional
+
+import redis
+
+from app.config import settings
+
+logger = logging.getLogger(__name__)
+
+
+# Feature identifiers. The public name is what the admin UI sends; the
+# ``yaml_default`` getter returns the value the YAML would have set.
+# Keep these in sync with the VisionSettings fields in ``config.py``.
+FLAG_VISION_ENABLED = 'vision.enabled'
+FLAG_OCR_ENABLED = 'vision.ocr.enabled'
+FLAG_DETECTOR_ENABLED = 'vision.detector.enabled'
+FLAG_FACES_ENABLED = 'vision.faces.enabled'
+FLAG_CLASSIFIER_ENABLED = 'vision.classifier.enabled'
+
+ALL_FLAGS = (
+    FLAG_VISION_ENABLED,
+    FLAG_OCR_ENABLED,
+    FLAG_DETECTOR_ENABLED,
+    FLAG_FACES_ENABLED,
+    FLAG_CLASSIFIER_ENABLED,
+)
+
+
+_REDIS: Optional[redis.Redis] = None
+
+
+def _redis() -> Optional[redis.Redis]:
+    """Lazy Redis client. Returns None if the broker is unreachable so
+    callers can fall back to YAML defaults instead of crashing."""
+    global _REDIS
+    if _REDIS is None:
+        try:
+            _REDIS = redis.Redis.from_url(
+                settings.celery_broker_url, decode_responses=True
+            )
+            _REDIS.ping()
+        except Exception as e:
+            logger.warning(f"feature_flags: Redis unavailable, using YAML defaults ({e})")
+            _REDIS = None
+    return _REDIS
+
+
+def _yaml_default(name: str) -> bool:
+    """Return the YAML-configured default for a flag. Used when Redis
+    has no value set (fresh install or admin never touched the tab)."""
+    v = settings.vision
+    if name == FLAG_VISION_ENABLED:
+        return bool(v.enabled)
+    if name == FLAG_OCR_ENABLED:
+        return bool(v.ocr.enabled)
+    if name == FLAG_DETECTOR_ENABLED:
+        return bool(v.detector.enabled)
+    if name == FLAG_FACES_ENABLED:
+        return bool(v.faces.enabled)
+    if name == FLAG_CLASSIFIER_ENABLED:
+        return bool(v.classifier.enabled)
+    raise ValueError(f"Unknown feature flag: {name!r}")
+
+
+def _redis_key(name: str) -> str:
+    return f"mulita:flags:{name}"
+
+
+def is_enabled(name: str) -> bool:
+    """Return True if feature ``name`` is currently enabled.
+
+    Order of precedence:
+      1. Redis override (set by PATCH /admin/feature-flags)
+      2. YAML default
+
+    Reads are cheap (~ms) and we intentionally do NOT add a local
+    process cache — the whole point of runtime flags is that a toggle
+    takes effect on the next task without a worker restart.
+    """
+    r = _redis()
+    if r is not None:
+        try:
+            raw = r.get(_redis_key(name))
+            if raw is not None:
+                return raw.lower() == 'true'
+        except Exception as e:
+            logger.warning(f"feature_flags: Redis read failed for {name} ({e})")
+    return _yaml_default(name)
+
+
+def set_flag(name: str, value: bool) -> None:
+    """Persist a flag override to Redis. No-op if Redis is unreachable
+    (we don't silently pretend to have written; raise so the admin
+    request returns a 500 instead of misleading success)."""
+    if name not in ALL_FLAGS:
+        raise ValueError(f"Unknown feature flag: {name!r}")
+    r = _redis()
+    if r is None:
+        raise RuntimeError("Redis unavailable; cannot update feature flags")
+    r.set(_redis_key(name), 'true' if value else 'false')
+    _apply_worker_side_effects(name)
+
+
+def reset_flag(name: str) -> None:
+    """Delete the Redis override so the flag falls back to its YAML
+    default. Useful if an admin wants a clean slate without guessing
+    what the config defaults are."""
+    if name not in ALL_FLAGS:
+        raise ValueError(f"Unknown feature flag: {name!r}")
+    r = _redis()
+    if r is None:
+        raise RuntimeError("Redis unavailable; cannot reset feature flags")
+    r.delete(_redis_key(name))
+    _apply_worker_side_effects(name)
+
+
+# ---------------------------------------------------------------------------
+# Worker-level side effects: when the admin flips a flag we don't just want
+# gating at task-start (which still executes the message, it just returns
+# 'skipped'). We also want queued work gone and the vision worker genuinely
+# idle when the master switch is off.
+# ---------------------------------------------------------------------------
+
+_VISION_QUEUE = 'vision'
+
+# Flag → celery task name(s) whose queued messages should be dropped when
+# the flag goes off. Keeps the queue from replaying yesterday's work the
+# moment someone re-enables the stage.
+_TASKS_BY_FLAG: dict[str, tuple[str, ...]] = {
+    FLAG_VISION_ENABLED: (
+        'embed_photo', 'ocr_photo', 'detect_objects', 'extract_faces',
+        'classify_content', 'vision_fanout', 'recluster_faces',
+    ),
+    FLAG_OCR_ENABLED: ('ocr_photo',),
+    FLAG_DETECTOR_ENABLED: ('detect_objects',),
+    FLAG_FACES_ENABLED: ('extract_faces', 'recluster_faces'),
+    FLAG_CLASSIFIER_ENABLED: ('classify_content',),
+}
+
+
+def _apply_worker_side_effects(name: str) -> None:
+    """Bring the live workers in line with the new flag value.
+
+    For the master ``vision.enabled`` flag we go beyond task gating and
+    actually stop consumption from the ``vision`` queue — flipping it
+    off puts the vision worker to sleep (no CPU, no model memory
+    churn) until it's flipped back on. For per-feature flags, the
+    running tasks already skip via ``is_enabled``; we just purge any
+    messages already sitting in the queue so the admin doesn't pay for
+    a backlog on re-enable.
+
+    All operations are best-effort — if control messaging or a Redis
+    op fails, we log and return; the flag state itself is already
+    persisted so the gating path continues to work.
+    """
+    try:
+        # Lazy import: avoids a circular dependency between the services
+        # module (imported from tasks.vision) and the celery app config.
+        from app.tasks.celery import celery_app
+    except Exception as e:
+        logger.warning(f"feature_flags: celery app unavailable for side effects ({e})")
+        return
+
+    try:
+        if name == FLAG_VISION_ENABLED:
+            if is_enabled(FLAG_VISION_ENABLED):
+                # Re-attach the vision consumer so workers pick up tasks
+                # again. broadcast=True ensures every running worker
+                # receives the command.
+                celery_app.control.add_consumer(_VISION_QUEUE, reply=False)
+                logger.info("feature_flags: vision re-enabled; consumer added")
+            else:
+                celery_app.control.cancel_consumer(_VISION_QUEUE, reply=False)
+                _purge_queue(_VISION_QUEUE)
+                logger.info(
+                    "feature_flags: vision disabled; consumer cancelled "
+                    "and queue purged"
+                )
+            return
+
+        # Per-feature flag going off → drop pending tasks of its types.
+        if not is_enabled(name):
+            targets = _TASKS_BY_FLAG.get(name, ())
+            if targets:
+                removed = _purge_queue_by_task_names(_VISION_QUEUE, targets)
+                logger.info(
+                    f"feature_flags: {name} disabled; removed {removed} "
+                    f"pending messages from {_VISION_QUEUE}"
+                )
+    except Exception as e:
+        logger.warning(f"feature_flags: worker side effects failed for {name}: {e}")
+
+
+def _purge_queue(queue: str) -> int:
+    """Drop every pending message from ``queue``. Returns the count
+    deleted. Celery's control.purge() purges the default queue only,
+    so we delete the Redis key directly (the broker's queue list)."""
+    r = _redis()
+    if r is None:
+        return 0
+    try:
+        removed = r.delete(queue)
+        return int(removed or 0)
+    except Exception as e:
+        logger.warning(f"feature_flags: purge {queue} failed: {e}")
+        return 0
+
+
+def _purge_queue_by_task_names(queue: str, task_names: tuple[str, ...]) -> int:
+    """Walk ``queue`` and drop any message whose Celery task name is in
+    ``task_names``. Other messages are preserved (pushed back in order)
+    so we don't flush embed tasks when the admin disabled only OCR.
+
+    Celery stores each message as a JSON blob in a Redis list; the
+    task name lives at ``headers.task``.
+    """
+    import json
+    r = _redis()
+    if r is None:
+        return 0
+    try:
+        # Snapshot the queue, then rebuild it without the filtered names.
+        # Done inside a Redis transaction so a concurrent enqueue doesn't
+        # race with us (worst case it gets re-delivered after we release,
+        # which is the normal enqueue path anyway).
+        pipe = r.pipeline()
+        pipe.lrange(queue, 0, -1)
+        pipe.delete(queue)
+        raw_items, _ = pipe.execute()
+        kept: list[bytes | str] = []
+        removed = 0
+        for raw in raw_items or []:
+            try:
+                # Messages can be bytes or str depending on decode_responses.
+                payload = raw.decode() if isinstance(raw, bytes) else raw
+                msg = json.loads(payload)
+                task = (
+                    msg.get('headers', {}).get('task')
+                    or msg.get('task')
+                )
+                if task in task_names:
+                    removed += 1
+                    continue
+            except Exception:
+                # Unparseable message — keep it, better to leak than
+                # to silently drop a message we can't identify.
+                pass
+            kept.append(raw)
+        if kept:
+            r.rpush(queue, *kept)
+        return removed
+    except Exception as e:
+        logger.warning(f"feature_flags: selective purge failed on {queue}: {e}")
+        return 0
+
+
+def snapshot() -> dict[str, dict[str, object]]:
+    """Return every flag's current effective value, YAML default, and
+    whether it's overridden. Powers the admin UI tab.
+    """
+    r = _redis()
+    out: dict[str, dict[str, object]] = {}
+    for name in ALL_FLAGS:
+        default = _yaml_default(name)
+        override = None
+        if r is not None:
+            try:
+                raw = r.get(_redis_key(name))
+                if raw is not None:
+                    override = raw.lower() == 'true'
+            except Exception:
+                pass
+        out[name] = {
+            'effective': override if override is not None else default,
+            'default': default,
+            'overridden': override is not None,
+        }
+    return out
diff --git a/backend/app/tasks/thumbs.py b/backend/app/tasks/thumbs.py
index 6626a0e..cd70e34 100644
--- a/backend/app/tasks/thumbs.py
+++ b/backend/app/tasks/thumbs.py
@@ -312,7 +312,25 @@ async def _generate_thumbnails_async(photo_id: str, task):
             else:
                 logger.error(f"Unsupported media type: {photo.media_type}")
                 image = create_placeholder_thumbnail(photo.media_type)
-            
+
+            # Fallback: some files wear a RAW/HEIC extension but are actually
+            # plain JPEGs — e.g. iPhones that write ProRAW-style .DNG for
+            # images where no RAW sensor data was captured, or re-exports
+            # that kept the original suffix. Pillow can open them directly,
+            # so before giving up, try reading the file as a standard image.
+            if not image and photo.media_type in ('raw', 'heic'):
+                try:
+                    image = process_standard_image(photo.filepath)
+                    if image is not None:
+                        logger.info(
+                            f"{photo.filepath}: {photo.media_type} decode failed "
+                            f"but file opens as a standard image — using fallback"
+                        )
+                except Exception as e:
+                    logger.debug(
+                        f"Standard-image fallback failed for {photo.filepath}: {e}"
+                    )
+
             if not image:
                 raise Exception("Failed to process image")
             
@@ -493,7 +511,16 @@ async def _backfill_phashes_async():
     }
 
 
-@shared_task(name='regroup_duplicates')
+@shared_task(
+    name='regroup_duplicates',
+    # Full regroup scales with O(N²) on phash plus one pgvector query per
+    # embedded photo. On a 16k-photo library that's comfortably past the
+    # default 5-minute soft limit — bump to 2h / 2h30m. (Passing None here
+    # does NOT disable limits; Celery falls back to the worker default
+    # of 300s/600s. An explicit number overrides.)
+    soft_time_limit=7200,
+    time_limit=9000,
+)
 def regroup_duplicates_task():
     """Full recompute of duplicate groups (pHash + CLIP similarity).
 
@@ -502,7 +529,15 @@ def regroup_duplicates_task():
     return asyncio.run(regroup_duplicates())
 
 
-@shared_task(name='incremental_regroup_duplicates')
+@shared_task(
+    name='incremental_regroup_duplicates',
+    # O(new × N); still cheaper than a full regroup but can easily exceed
+    # the 5-minute default after a big batch import. Same caveat as
+    # regroup_duplicates above — None would just re-inherit the worker
+    # default, so we pass explicit values.
+    soft_time_limit=3600,
+    time_limit=4200,
+)
 def incremental_regroup_duplicates_task(since_iso: str | None = None):
     """Incremental duplicate detection for newly added photos.
 
diff --git a/backend/app/tasks/vision.py b/backend/app/tasks/vision.py
index 412dfe4..112655d 100644
--- a/backend/app/tasks/vision.py
+++ b/backend/app/tasks/vision.py
@@ -20,6 +20,14 @@ from PIL import Image
 
 from app.models.embeddings import Embedding
 from app.config import settings
+from app.services.feature_flags import (
+    is_enabled,
+    FLAG_VISION_ENABLED,
+    FLAG_OCR_ENABLED,
+    FLAG_DETECTOR_ENABLED,
+    FLAG_FACES_ENABLED,
+    FLAG_CLASSIFIER_ENABLED,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -83,7 +91,7 @@ def _load_thumb(photo_id: str, size: str = "medium") -> np.ndarray | None:
 @shared_task(name='embed_photo', queue='vision', bind=True, max_retries=3)
 def embed_photo(self, photo_id: str):
     """Generate CLIP embedding for a photo and store in pgvector."""
-    if not settings.vision.enabled:
+    if not is_enabled(FLAG_VISION_ENABLED):
         return {'status': 'skipped', 'reason': 'vision disabled'}
 
     image = _load_thumb(photo_id, "medium")  # 640px
@@ -128,18 +136,18 @@ def embed_photo(self, photo_id: str):
 @shared_task(name='vision_fanout', queue='vision')
 def vision_fanout(photo_id: str):
     """Dispatch all enabled vision tasks for a photo."""
-    if not settings.vision.enabled:
+    if not is_enabled(FLAG_VISION_ENABLED):
         return {'status': 'skipped', 'reason': 'vision disabled'}
 
     embed_photo.delay(photo_id)
 
-    if settings.vision.ocr.enabled:
+    if is_enabled(FLAG_OCR_ENABLED):
         ocr_photo.delay(photo_id)
-    if settings.vision.detector.enabled:
+    if is_enabled(FLAG_DETECTOR_ENABLED):
         detect_objects.delay(photo_id)
-    if settings.vision.faces.enabled:
+    if is_enabled(FLAG_FACES_ENABLED):
         extract_faces.delay(photo_id)
-    if settings.vision.classifier.enabled:
+    if is_enabled(FLAG_CLASSIFIER_ENABLED):
         classify_content.delay(photo_id)
 
     return {'status': 'dispatched', 'photo_id': photo_id}
@@ -148,7 +156,7 @@ def vision_fanout(photo_id: str):
 @shared_task(name='ocr_photo', queue='vision', bind=True, max_retries=3)
 def ocr_photo(self, photo_id: str):
     """Run OCR on a photo and store text regions."""
-    if not settings.vision.enabled or not settings.vision.ocr.enabled:
+    if not is_enabled(FLAG_VISION_ENABLED) or not is_enabled(FLAG_OCR_ENABLED):
         return {'status': 'skipped', 'reason': 'OCR disabled'}
 
     image = _load_thumb(photo_id, "large")  # 1280px for better OCR accuracy
@@ -195,7 +203,7 @@ def ocr_photo(self, photo_id: str):
 def detect_objects(self, photo_id: str):
     """Detect objects in a photo, create Tag(kind=object) rows, and
     link via photo_tags with confidence/bbox/source."""
-    if not settings.vision.enabled or not settings.vision.detector.enabled:
+    if not is_enabled(FLAG_VISION_ENABLED) or not is_enabled(FLAG_DETECTOR_ENABLED):
         return {'status': 'skipped', 'reason': 'detection disabled'}
 
     image = _load_thumb(photo_id, "medium")  # 640px
@@ -279,7 +287,7 @@ def detect_objects(self, photo_id: str):
 def classify_content(self, photo_id: str):
     """Classify image content type (screenshot, document, artwork, etc.)
     using CLIP zero-shot classification. Writes Tag(kind=content_type)."""
-    if not settings.vision.enabled or not settings.vision.classifier.enabled:
+    if not is_enabled(FLAG_VISION_ENABLED) or not is_enabled(FLAG_CLASSIFIER_ENABLED):
         return {'status': 'skipped', 'reason': 'classifier disabled'}
 
     image = _load_thumb(photo_id, "medium")
@@ -394,7 +402,7 @@ def extract_faces(self, photo_id: str):
     """Detect faces and store recognition embeddings using InsightFace
     (RetinaFace + ArcFace). No YOLO workaround needed — RetinaFace has
     strong human-vs-non-human precision on its own."""
-    if not settings.vision.enabled or not settings.vision.faces.enabled:
+    if not is_enabled(FLAG_VISION_ENABLED) or not is_enabled(FLAG_FACES_ENABLED):
         return {'status': 'skipped', 'reason': 'faces disabled'}
 
     image = _load_original(photo_id)
@@ -478,7 +486,7 @@ def recluster_faces(self):
         logger.info("Vision worker not ready yet — retrying in 30s")
         raise self.retry(countdown=30)
 
-    if not settings.vision.enabled or not settings.vision.faces.enabled:
+    if not is_enabled(FLAG_VISION_ENABLED) or not is_enabled(FLAG_FACES_ENABLED):
         return {'status': 'skipped', 'reason': 'faces disabled'}
 
     from app.models import Photo
@@ -603,7 +611,7 @@ def backfill_vision(self, task: str | None = None, limit: int | None = None):
             embed_ids = [r[0] for r in session.execute(sa_text(sql), params).fetchall()]
 
         ocr_ids = []
-        if task in ('ocr', None) and settings.vision.ocr.enabled:
+        if task in ('ocr', None) and is_enabled(FLAG_OCR_ENABLED):
             sql = f"""
                 SELECT p.id FROM photos p
                 LEFT JOIN ocr_text o ON o.photo_id = p.id
@@ -613,7 +621,7 @@ def backfill_vision(self, task: str | None = None, limit: int | None = None):
             ocr_ids = [r[0] for r in session.execute(sa_text(sql), params).fetchall()]
 
         detect_ids = []
-        if task in ('detect', None) and settings.vision.detector.enabled:
+        if task in ('detect', None) and is_enabled(FLAG_DETECTOR_ENABLED):
             sql = f"""
                 SELECT p.id FROM photos p
                 WHERE p.processing_status = 'completed'
@@ -626,7 +634,7 @@ def backfill_vision(self, task: str | None = None, limit: int | None = None):
             detect_ids = [r[0] for r in session.execute(sa_text(sql), params).fetchall()]
 
         face_ids = []
-        if task in ('faces', None) and settings.vision.faces.enabled:
+        if task in ('faces', None) and is_enabled(FLAG_FACES_ENABLED):
             sql = f"""
                 SELECT p.id FROM photos p
                 LEFT JOIN face_embeddings fe ON fe.photo_id = p.id
@@ -636,7 +644,7 @@ def backfill_vision(self, task: str | None = None, limit: int | None = None):
             face_ids = [r[0] for r in session.execute(sa_text(sql), params).fetchall()]
 
         classify_ids = []
-        if task in ('classify', None) and settings.vision.classifier.enabled:
+        if task in ('classify', None) and is_enabled(FLAG_CLASSIFIER_ENABLED):
             sql = f"""
                 SELECT p.id FROM photos p
                 WHERE p.processing_status = 'completed'
diff --git a/backend/requirements.txt b/backend/requirements.txt
index 780e53b..e9db2bc 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -18,7 +18,12 @@ flower==2.0.1
 
 # Image processing
 # pyvips==2.2.1  # Optional - having compatibility issues, using Pillow as fallback
-# rawpy==0.19.0  # Optional - numpy compatibility issues, using Pillow as fallback
+rawpy==0.26.1               # RAW decoder (CR2/NEF/ARW/DNG/…). cp312 wheels
+                            # ship with libraw bundled; the older 0.19 pin
+                            # had numpy 2.x incompatibilities — 0.26 is fine
+                            # with our numpy 1.26. iPhone ProRAW-style DNGs
+                            # that aren't real RAW still fail here; thumbs.py
+                            # falls back to opening them as JPEG in that case.
 pillow==10.2.0
 pillow-heif==0.15.0
 imagehash==4.3.1  # perceptual hash for duplicate detection
diff --git a/frontend/src/components/dialogs/SettingsDialog.tsx b/frontend/src/components/dialogs/SettingsDialog.tsx
index 2c8f92d..dcb0f31 100644
--- a/frontend/src/components/dialogs/SettingsDialog.tsx
+++ b/frontend/src/components/dialogs/SettingsDialog.tsx
@@ -15,15 +15,23 @@ import {
   Activity,
   FolderSearch,
   Shield,
+  Brain,
+  ScanText,
+  UserSquare2,
+  Boxes,
+  Tags as TagsIcon,
+  RotateCcw,
 } from 'lucide-react'
 import clsx from 'clsx'
 import { useQuery, useQueryClient } from '@tanstack/react-query'
 import {
   library,
+  admin as adminApi,
   type MediaType,
   type PipelineStage,
   type ScanStatus,
   type WorkerStatus,
+  type FeatureFlagSnapshot,
 } from '../../services/api'
 import { toast } from '../ToastContainer'
 import { useAuth } from '../../contexts/AuthContext'
@@ -42,13 +50,16 @@ const SETTINGS_SCAN_STATUS_KEY = ['settings', 'scan-status'] as const
 // the grid renders from. Imported via the canonical hook key.
 import { DUPLICATE_GROUPS_QUERY_KEY } from '../../hooks/useDuplicateGroupsQuery'
 
-type SettingsTab = 'library' | 'users'
+type SettingsTab = 'library' | 'ai' | 'users'
 
 const TABS: { id: SettingsTab; label: string; adminOnly?: boolean }[] = [
   { id: 'library', label: 'Library Management' },
+  { id: 'ai', label: 'AI Features', adminOnly: true },
   { id: 'users', label: 'Users', adminOnly: true },
 ]
 
+const SETTINGS_FEATURE_FLAGS_KEY = ['settings', 'feature-flags'] as const
+
 /**
  * Full-page settings view with tabbed navigation. Replaces the old
  * modal dialog — renders as a top-level section in the main content
@@ -842,6 +853,13 @@ export function SettingsPage() {
             </Section>
         </>)}
 
+        {activeTab === 'ai' && isAdmin && (
+          <AiFeaturesTab
+            busy={busy}
+            runAction={runAction}
+          />
+        )}
+
         {activeTab === 'users' && isAdmin && (
             <Section
               icon={<Shield className="h-4 w-4" />}
@@ -1073,3 +1091,267 @@ function ActionButton({
     </button>
   )
 }
+
+
+// ---------------------------------------------------------------------------
+// AI Features admin tab
+// ---------------------------------------------------------------------------
+
+interface AiFeaturesTabProps {
+  busy: Record<string, boolean>
+  runAction: <T>(
+    key: string,
+    fn: () => Promise<T>,
+    successTitle: string,
+    describe?: (result: T) => string | undefined,
+  ) => Promise<void>
+}
+
+// Flags are keyed by the backend's canonical name ("vision.enabled",
+// "vision.ocr.enabled", ...). The metadata here just adds presentation
+// (label, short description, icon) so the tab layout stays data-driven.
+const FLAG_META: Array<{
+  id: string
+  label: string
+  description: string
+  icon: React.ReactNode
+  // Optional "run this backfill" hook — lets the user kick off a stage's
+  // backfill right from the toggle row without hopping to a separate UI.
+  backfillTask?: 'embed' | 'ocr' | 'detect' | 'faces' | 'classify'
+}> = [
+  {
+    id: 'vision.enabled',
+    label: 'Vision pipeline (master switch)',
+    description:
+      'When off, every AI stage below is skipped — including newly uploaded photos. ' +
+      'Existing results stay intact.',
+    icon: <Sparkles className="h-3.5 w-3.5" />,
+  },
+  {
+    id: 'vision.ocr.enabled',
+    label: 'Text recognition (OCR)',
+    description: 'Extract printed / handwritten text from photos so it becomes searchable.',
+    icon: <ScanText className="h-3.5 w-3.5" />,
+    backfillTask: 'ocr',
+  },
+  {
+    id: 'vision.detector.enabled',
+    label: 'Object detection',
+    description: 'Tag photos with detected objects (person, car, dog, …) via YOLOv8n.',
+    icon: <Boxes className="h-3.5 w-3.5" />,
+    backfillTask: 'detect',
+  },
+  {
+    id: 'vision.faces.enabled',
+    label: 'Face recognition',
+    description:
+      'Find and cluster faces across the library (RetinaFace + ArcFace). ' +
+      'Expensive on big libraries — disable if you don\'t need the People view.',
+    icon: <UserSquare2 className="h-3.5 w-3.5" />,
+    backfillTask: 'faces',
+  },
+  {
+    id: 'vision.classifier.enabled',
+    label: 'Content classification',
+    description: 'Zero-shot CLIP tags for scenes / activities (beach, wedding, …).',
+    icon: <TagsIcon className="h-3.5 w-3.5" />,
+    backfillTask: 'classify',
+  },
+]
+
+function AiFeaturesTab({ busy, runAction }: AiFeaturesTabProps) {
+  const queryClient = useQueryClient()
+  const flagsQuery = useQuery<{ flags: FeatureFlagSnapshot }>({
+    queryKey: SETTINGS_FEATURE_FLAGS_KEY,
+    queryFn: adminApi.listFeatureFlags,
+    staleTime: 5_000,
+  })
+
+  const flags = flagsQuery.data?.flags ?? {}
+  const masterOff = flags['vision.enabled'] && !flags['vision.enabled'].effective
+
+  const applyFlag = async (name: string, value: boolean | null) => {
+    await runAction(
+      `flag:${name}`,
+      () => adminApi.setFeatureFlag(name, value),
+      value === null ? 'Override cleared' : `Feature ${value ? 'enabled' : 'disabled'}`,
+    )
+    queryClient.invalidateQueries({ queryKey: SETTINGS_FEATURE_FLAGS_KEY })
+    // Non-admin feature map drives sidebar gating — invalidate so the
+    // People / Tags entries appear / disappear immediately without a
+    // page reload.
+    queryClient.invalidateQueries({ queryKey: ['features'] })
+  }
+
+  type BackfillTask = 'embed' | 'ocr' | 'detect' | 'faces' | 'classify' | null
+  const runBackfill = (task: BackfillTask) =>
+    runAction(
+      `ai-backfill:${task ?? 'all'}`,
+      () => adminApi.triggerAiBackfill({ task }),
+      task ? `Backfill queued for ${task}` : 'Full backfill queued',
+      (r) => `Celery task ${r.task_id}`,
+    )
+
+  return (
+    <>
+      <Section icon={<Brain className="h-4 w-4" />} title="AI feature flags">
+        <p className="text-xs text-text-muted">
+          Toggle each stage at runtime. Changes are observed by Celery
+          workers on the next task — no restart needed. "Default" means
+          the flag hasn\'t been overridden and is tracking the YAML config;
+          an overridden flag is pinned to the value shown until cleared.
+        </p>
+
+        {flagsQuery.isLoading && (
+          <div className="mt-3 flex items-center gap-2 text-xs text-text-muted">
+            <Loader2 className="h-3 w-3 animate-spin" />
+            Loading feature flags…
+          </div>
+        )}
+        {flagsQuery.error && (
+          <ErrorBanner
+            title="Could not load feature flags"
+            detail={String((flagsQuery.error as Error).message || flagsQuery.error)}
+          />
+        )}
+
+        {!flagsQuery.isLoading && !flagsQuery.error && (
+          <div className="mt-3 space-y-2">
+            {FLAG_META.map((meta) => {
+              const state = flags[meta.id]
+              if (!state) return null
+              const busyKey = `flag:${meta.id}`
+              const isBusy = !!busy[busyKey]
+              const isMaster = meta.id === 'vision.enabled'
+              const dimmed = !isMaster && masterOff
+              return (
+                <div
+                  key={meta.id}
+                  className={clsx(
+                    'rounded border border-border bg-surface p-3 text-xs',
+                    dimmed && 'opacity-60',
+                  )}
+                >
+                  <div className="flex items-start justify-between gap-3">
+                    <div className="min-w-0 flex-1">
+                      <div className="flex items-center gap-1.5 text-text">
+                        {meta.icon}
+                        <span className="font-medium">{meta.label}</span>
+                        {state.overridden && (
+                          <span className="rounded bg-primary/20 px-1 py-0.5 text-[9px] font-semibold uppercase tracking-wide text-primary">
+                            overridden
+                          </span>
+                        )}
+                      </div>
+                      <p className="mt-1 text-[11px] text-text-muted">{meta.description}</p>
+                      <p className="mt-1 text-[10px] text-text-faint">
+                        Default: {state.default ? 'on' : 'off'} · Currently:{' '}
+                        <span className={state.effective ? 'text-pick' : 'text-reject'}>
+                          {state.effective ? 'on' : 'off'}
+                        </span>
+                      </p>
+                    </div>
+                    <div className="flex shrink-0 items-center gap-2">
+                      <button
+                        role="switch"
+                        aria-checked={state.effective}
+                        onClick={() => applyFlag(meta.id, !state.effective)}
+                        disabled={isBusy || (dimmed && !isMaster)}
+                        className={clsx(
+                          'relative inline-flex h-6 w-11 shrink-0 items-center rounded-full transition-colors',
+                          state.effective ? 'bg-primary' : 'bg-surface-2 border border-border',
+                          (isBusy || (dimmed && !isMaster)) && 'cursor-not-allowed opacity-50',
+                        )}
+                        title={state.effective ? 'Click to disable' : 'Click to enable'}
+                      >
+                        <span
+                          aria-hidden="true"
+                          className={clsx(
+                            'inline-block h-5 w-5 transform rounded-full bg-white shadow transition-transform',
+                            state.effective ? 'translate-x-[22px]' : 'translate-x-0.5',
+                          )}
+                        />
+                      </button>
+                      {state.overridden && (
+                        <button
+                          onClick={() => applyFlag(meta.id, null)}
+                          disabled={isBusy}
+                          className="rounded border border-border p-1 text-text-muted hover:bg-surface-2 hover:text-text disabled:opacity-50"
+                          title="Reset to YAML default"
+                          aria-label="Reset override"
+                        >
+                          <RotateCcw className="h-3 w-3" />
+                        </button>
+                      )}
+                    </div>
+                  </div>
+
+                  {meta.backfillTask && state.effective && !masterOff && (
+                    <div className="mt-2">
+                      <ActionButton
+                        loading={!!busy[`ai-backfill:${meta.backfillTask}`]}
+                        onClick={() => runBackfill(meta.backfillTask!)}
+                      >
+                        <RefreshCw className="h-3.5 w-3.5" />
+                        Run {meta.backfillTask} backfill
+                      </ActionButton>
+                    </div>
+                  )}
+                </div>
+              )
+            })}
+          </div>
+        )}
+      </Section>
+
+      <Section icon={<Cpu className="h-4 w-4" />} title="Manual pipeline triggers">
+        <p className="text-xs text-text-muted">
+          Run a full pass across the enabled stages, recompute face
+          clusters, or force a fresh filesystem scan. All three are safe
+          to run repeatedly — the backfill only touches photos that
+          don\'t yet have a given output, and the rescan skips files
+          that are already indexed.
+        </p>
+        <div className="mt-3 flex flex-wrap gap-2">
+          <ActionButton
+            loading={!!busy['ai-backfill:all']}
+            onClick={() => runBackfill(null)}
+            disabled={masterOff}
+          >
+            <Sparkles className="h-4 w-4" />
+            Run full vision backfill
+          </ActionButton>
+          <ActionButton
+            loading={!!busy['recluster']}
+            onClick={() =>
+              runAction(
+                'recluster',
+                () => adminApi.triggerFaceRecluster(),
+                'Face recluster queued',
+                (r) => `Celery task ${r.task_id}`,
+              )
+            }
+            disabled={masterOff || !flags['vision.faces.enabled']?.effective}
+          >
+            <UserSquare2 className="h-4 w-4" />
+            Recluster faces
+          </ActionButton>
+          <ActionButton
+            loading={!!busy['rescan-full']}
+            onClick={() =>
+              runAction(
+                'rescan-full',
+                () => adminApi.triggerFullRescan(),
+                'Rescan queued',
+                (r) => `Celery task ${r.task_id}`,
+              )
+            }
+          >
+            <RefreshCw className="h-4 w-4" />
+            Rescan all source roots
+          </ActionButton>
+        </div>
+      </Section>
+    </>
+  )
+}
diff --git a/frontend/src/components/heaps/HeapsPanel.tsx b/frontend/src/components/heaps/HeapsPanel.tsx
index 125f750..53dd589 100644
--- a/frontend/src/components/heaps/HeapsPanel.tsx
+++ b/frontend/src/components/heaps/HeapsPanel.tsx
@@ -11,12 +11,13 @@ import {
   Copy,
   Trash2,
   Users,
+  Download as DownloadIcon,
 } from 'lucide-react'
 import clsx from 'clsx'
 import { useMutation, useQueryClient } from '@tanstack/react-query'
 import { useHeapsQuery, HEAPS_QUERY_KEY } from '../../hooks/useHeapsQuery'
 import { useSharedHeapsQuery } from '../../hooks/useSharingQueries'
-import { heaps as heapsApi, type Heap } from '../../services/api'
+import { heaps as heapsApi, downloads, type Heap } from '../../services/api'
 import { useFilterStore } from '../../store/filterStore'
 import { toast } from '../ToastContainer'
 import { PHOTO_DRAG_MIME } from '../timeline/PhotoThumbnail'
@@ -448,6 +449,14 @@ export function HeapsPanel() {
                           setSharingHeap(heap)
                         }}
                       />
+                      <MenuItem
+                        icon={<DownloadIcon className="h-3.5 w-3.5" />}
+                        label="Download as zip"
+                        onClick={() => {
+                          setOpenMenuId(null)
+                          downloads.trigger(downloads.heapUrl(heap.id))
+                        }}
+                      />
                       <div className="my-1 h-px bg-border" />
                       <MenuItem
                         icon={<Trash2 className="h-3.5 w-3.5" />}
diff --git a/frontend/src/components/layout/LeftSidebar.tsx b/frontend/src/components/layout/LeftSidebar.tsx
index c07ff4d..f79dc47 100644
--- a/frontend/src/components/layout/LeftSidebar.tsx
+++ b/frontend/src/components/layout/LeftSidebar.tsx
@@ -24,9 +24,11 @@ import {
   LogOut,
   Shield,
   Clock,
+  Upload as UploadIcon,
+  Download as DownloadIcon,
 } from 'lucide-react'
 import clsx from 'clsx'
-import { sourceFolders, photos as photosApi, type FolderTreeNode } from '../../services/api'
+import { sourceFolders, photos as photosApi, downloads, type FolderTreeNode } from '../../services/api'
 import { useMutation, useQueryClient } from '@tanstack/react-query'
 import { toast } from '../ToastContainer'
 import { useFilterStore } from '../../store/filterStore'
@@ -45,8 +47,10 @@ import { registerUndoable } from '../../store/undoStore'
 import type { Photo } from '../../types/photo'
 import { DeleteFolderDialog } from '../dialogs/DeleteFolderDialog'
 import { ShareDialog } from '../sharing/ShareDialog'
+import { UploadModal } from '../upload/UploadModal'
 import { useSharedFoldersQuery } from '../../hooks/useSharingQueries'
 import { useAuth } from '../../contexts/AuthContext'
+import { useFeaturesQuery } from '../../hooks/useFeaturesQuery'
 
 interface TreeItem {
   id: string
@@ -78,6 +82,15 @@ export function LeftSidebar({ onCollapse }: LeftSidebarProps) {
   const { data: allTags = [] } = useTagsQuery()
   const { data: faceClusters = [] } = useTagsQuery('face_cluster')
   const { data: stats } = useLibraryStatsQuery()
+  const { data: featuresMap } = useFeaturesQuery()
+  const visionOn = featuresMap ? featuresMap['vision.enabled'] !== false : true
+  const facesOn = visionOn && (featuresMap ? featuresMap['vision.faces.enabled'] !== false : true)
+  const tagsOn =
+    visionOn &&
+    (featuresMap
+      ? featuresMap['vision.detector.enabled'] !== false ||
+        featuresMap['vision.classifier.enabled'] !== false
+      : true)
   const [dropTargetId, setDropTargetId] = useState<string | null>(null)
 
   // Per-folder kebab menu open state. Stores the tree-item id ("folder-..."
@@ -117,6 +130,14 @@ export function LeftSidebar({ onCollapse }: LeftSidebarProps) {
     id: string
     name: string
   } | null>(null)
+  // Upload modal state. `uploadTarget` stores the pre-selected
+  // destination Folder/SourceRoot id so "Upload here…" on a folder row
+  // drops files straight into that folder; null means the general
+  // Library-level button (defaults to the first source root).
+  const [uploadTarget, setUploadTarget] = useState<{ open: boolean; folderId: string | null }>({
+    open: false,
+    folderId: null,
+  })
   const { data: sharedFolders = [] } = useSharedFoldersQuery()
 
   // Bulk discard mutation for the drag-onto-Discarded interaction.
@@ -414,8 +435,8 @@ export function LeftSidebar({ onCollapse }: LeftSidebarProps) {
       children: [
         { id: 'all-photos', label: 'All Photos', icon: <Image className="h-4 w-4" />, count: stats?.all_photos ?? 0 },
         { id: 'rated', label: 'Rated', icon: <Star className="h-4 w-4" />, count: stats?.rated ?? 0 },
-        { id: 'tags', label: 'Tags', icon: <TagIcon className="h-4 w-4" />, count: tagsTotalCount },
-        { id: 'people', label: 'People', icon: <Users className="h-4 w-4" />, count: peopleTotalCount },
+        ...(tagsOn ? [{ id: 'tags', label: 'Tags', icon: <TagIcon className="h-4 w-4" />, count: tagsTotalCount }] : []),
+        ...(facesOn ? [{ id: 'people', label: 'People', icon: <Users className="h-4 w-4" />, count: peopleTotalCount }] : []),
         { id: 'colors', label: 'Colors', icon: <Palette className="h-4 w-4" />, count: stats?.colored ?? 0 },
         { id: 'map', label: 'Map', icon: <MapPin className="h-4 w-4" />, count: stats?.with_gps ?? 0 },
         { id: 'memories', label: 'Memories', icon: <Clock className="h-4 w-4" /> },
@@ -670,6 +691,14 @@ export function LeftSidebar({ onCollapse }: LeftSidebarProps) {
                       onClick={(e) => e.stopPropagation()}
                       className="absolute right-0 top-full z-30 mt-1 min-w-[180px] overflow-hidden rounded-lg border border-border bg-surface py-1 text-sm shadow-xl"
                     >
+                      <FolderMenuItem
+                        icon={<UploadIcon className="h-3.5 w-3.5" />}
+                        label="Upload here…"
+                        onClick={() => {
+                          setOpenMenuId(null)
+                          setUploadTarget({ open: true, folderId })
+                        }}
+                      />
                       <FolderMenuItem
                         icon={<FolderPlus className="h-3.5 w-3.5" />}
                         label="New sub-folder"
@@ -718,6 +747,14 @@ export function LeftSidebar({ onCollapse }: LeftSidebarProps) {
                           setSharingFolder({ id: folderId, name: item.label })
                         }}
                       />
+                      <FolderMenuItem
+                        icon={<DownloadIcon className="h-3.5 w-3.5" />}
+                        label="Download as zip"
+                        onClick={() => {
+                          setOpenMenuId(null)
+                          downloads.trigger(downloads.folderUrl(folderId))
+                        }}
+                      />
                       <div className="my-1 h-px bg-border" />
                       <FolderMenuItem
                         icon={<Trash2 className="h-3.5 w-3.5" />}
@@ -801,14 +838,24 @@ export function LeftSidebar({ onCollapse }: LeftSidebarProps) {
         <h2 className="text-[11px] font-semibold uppercase tracking-[0.14em] text-text-muted">
           Library
         </h2>
-        <button
-          onClick={onCollapse}
-          className="rounded p-0.5 text-text-muted hover:bg-surface-2 hover:text-text"
-          title="Collapse panel (Tab)"
-          aria-label="Collapse panel"
-        >
-          <PanelLeftClose className="h-3.5 w-3.5" />
-        </button>
+        <div className="flex items-center gap-1">
+          <button
+            onClick={() => setUploadTarget({ open: true, folderId: null })}
+            className="rounded p-0.5 text-text-muted hover:bg-surface-2 hover:text-text"
+            title="Upload photos"
+            aria-label="Upload photos"
+          >
+            <UploadIcon className="h-3.5 w-3.5" />
+          </button>
+          <button
+            onClick={onCollapse}
+            className="rounded p-0.5 text-text-muted hover:bg-surface-2 hover:text-text"
+            title="Collapse panel (Tab)"
+            aria-label="Collapse panel"
+          >
+            <PanelLeftClose className="h-3.5 w-3.5" />
+          </button>
+        </div>
       </div>
       {/* Active heap card — pinned just below the Library header so
        *  toasts (bottom-left fixed) can't cover it. Returns null when
@@ -922,6 +969,11 @@ export function LeftSidebar({ onCollapse }: LeftSidebarProps) {
         targetName={sharingFolder?.name ?? ''}
         onClose={() => setSharingFolder(null)}
       />
+      <UploadModal
+        isOpen={uploadTarget.open}
+        initialFolderId={uploadTarget.folderId}
+        onClose={() => setUploadTarget({ open: false, folderId: null })}
+      />
     </div>
   )
 }
diff --git a/frontend/src/components/upload/UploadModal.tsx b/frontend/src/components/upload/UploadModal.tsx
new file mode 100644
index 0000000..c2af59c
--- /dev/null
+++ b/frontend/src/components/upload/UploadModal.tsx
@@ -0,0 +1,608 @@
+import { useEffect, useMemo, useRef, useState } from 'react'
+import {
+  ChevronDown,
+  ChevronRight,
+  Folder as FolderIcon,
+  Upload as UploadIcon,
+  X,
+  FileImage,
+  CheckCircle2,
+  AlertCircle,
+} from 'lucide-react'
+import clsx from 'clsx'
+import { useQueryClient } from '@tanstack/react-query'
+import { uploads, type FolderTreeNode } from '../../services/api'
+import { useFolderTreeQuery } from '../../hooks/useFolderTreeQuery'
+import { useHeapsQuery, HEAPS_QUERY_KEY } from '../../hooks/useHeapsQuery'
+import { FOLDER_TREE_QUERY_KEY } from '../../hooks/useFolderTreeQuery'
+import { LIBRARY_STATS_QUERY_KEY } from '../../hooks/useLibraryStatsQuery'
+import { toast } from '../ToastContainer'
+
+interface UploadModalProps {
+  isOpen: boolean
+  onClose: () => void
+  /** Optional pre-selected destination. Accepts a Folder id or SourceRoot
+   *  id — the backend resolves source roots to their root Folder row. */
+  initialFolderId?: string | null
+}
+
+interface QueuedFile {
+  /** Stable key; the browser may give us multiple files with the same
+   *  name from different subfolders, so we key on index + path. */
+  key: string
+  file: File
+  relativePath: string
+  status: 'pending' | 'uploading' | 'done' | 'error'
+  progress: number
+  error?: string
+}
+
+const SUPPORTED_EXTENSIONS = new Set([
+  '.jpg', '.jpeg', '.png', '.tiff', '.tif', '.webp', '.bmp',
+  '.cr2', '.cr3', '.nef', '.arw', '.raf', '.dng', '.orf', '.rw2', '.pef', '.srw',
+  '.heic', '.heif',
+  '.mp4', '.mov', '.avi', '.mkv', '.mts', '.m2ts', '.3gp', '.wmv', '.flv',
+])
+
+function extOf(name: string): string {
+  const i = name.lastIndexOf('.')
+  return i === -1 ? '' : name.slice(i).toLowerCase()
+}
+
+function isSupported(name: string): boolean {
+  return SUPPORTED_EXTENSIONS.has(extOf(name))
+}
+
+const MAX_PARALLEL = 4
+
+/** Walk the tree to collect the ids on the path from root to `targetId`,
+ *  excluding the target itself — used to expand ancestor rows so a
+ *  pre-selected destination is visible. */
+function collectAncestors(tree: FolderTreeNode[], targetId: string): string[] {
+  const path: string[] = []
+  const walk = (nodes: FolderTreeNode[], chain: string[]): boolean => {
+    for (const n of nodes) {
+      if (n.id === targetId) {
+        path.push(...chain)
+        return true
+      }
+      if (n.children && walk(n.children, [...chain, n.id])) return true
+    }
+    return false
+  }
+  walk(tree, [])
+  return path
+}
+
+/**
+ * Upload from desktop. Supports:
+ *   - Dropping files or folders onto the drop zone
+ *   - Picking files with "Select files"
+ *   - Picking a whole folder with "Select folder" (webkitdirectory);
+ *     every file's webkitRelativePath is sent to the backend so sub-
+ *     folder structure is preserved under the chosen destination.
+ *
+ * Destination is a Folder row (or a source root, which the backend
+ * resolves to its root folder). An optional heap can also be chosen —
+ * uploaded photos are added to that heap in the same request.
+ */
+export function UploadModal({ isOpen, onClose, initialFolderId }: UploadModalProps) {
+  const queryClient = useQueryClient()
+  const { data: folderTree } = useFolderTreeQuery()
+  const { data: allHeaps = [] } = useHeapsQuery()
+
+  const [queue, setQueue] = useState<QueuedFile[]>([])
+  const [destFolderId, setDestFolderId] = useState<string | null>(null)
+  const [destHeapId, setDestHeapId] = useState<string | null>(null)
+  const [isUploading, setIsUploading] = useState(false)
+  const [dragOver, setDragOver] = useState(false)
+  const [expandedFolders, setExpandedFolders] = useState<Set<string>>(new Set())
+
+  const fileInputRef = useRef<HTMLInputElement>(null)
+  const dirInputRef = useRef<HTMLInputElement>(null)
+  const abortRef = useRef<AbortController | null>(null)
+
+  // Default destination: caller-provided initialFolderId wins; otherwise
+  // first source root in the tree. Re-runs when the modal is re-opened
+  // with a different initial target so the right row is highlighted.
+  useEffect(() => {
+    if (!isOpen) return
+    if (initialFolderId) {
+      setDestFolderId(initialFolderId)
+      // Expand every ancestor of the pre-selected folder so the row is
+      // actually visible in the tree.
+      if (folderTree) {
+        const ancestors = collectAncestors(folderTree, initialFolderId)
+        setExpandedFolders((prev) => new Set([...prev, ...ancestors]))
+      }
+      return
+    }
+    if (!destFolderId && folderTree && folderTree.length > 0) {
+      setDestFolderId(folderTree[0].id)
+      setExpandedFolders(new Set([folderTree[0].id]))
+    }
+  }, [isOpen, initialFolderId, folderTree, destFolderId])
+
+  // Esc closes (unless mid-upload — don't orphan in-flight requests).
+  useEffect(() => {
+    if (!isOpen) return
+    const handler = (e: KeyboardEvent) => {
+      if (e.key === 'Escape' && !isUploading) onClose()
+    }
+    window.addEventListener('keydown', handler)
+    return () => window.removeEventListener('keydown', handler)
+  }, [isOpen, isUploading, onClose])
+
+  // Reset transient state on open so a previous session's queue doesn't
+  // bleed into a fresh one.
+  useEffect(() => {
+    if (isOpen) {
+      setQueue([])
+      setIsUploading(false)
+    }
+  }, [isOpen])
+
+  const addFiles = (incoming: File[], relPathFn?: (f: File) => string) => {
+    const next: QueuedFile[] = []
+    let skipped = 0
+    for (const file of incoming) {
+      const relPath = (relPathFn?.(file) ?? '').replace(/\\/g, '/').replace(/^\/+/, '')
+      const filename = relPath || file.name
+      if (!isSupported(filename)) {
+        skipped++
+        continue
+      }
+      next.push({
+        key: `${relPath || file.name}::${file.size}::${file.lastModified}::${next.length}`,
+        file,
+        relativePath: relPath,
+        status: 'pending',
+        progress: 0,
+      })
+    }
+    if (skipped > 0) {
+      toast.info?.(`Skipped ${skipped} unsupported file${skipped === 1 ? '' : 's'}`)
+    }
+    setQueue((prev) => [...prev, ...next])
+  }
+
+  const handleFilePick = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const files = Array.from(e.target.files ?? [])
+    addFiles(files, (f) => f.name) // no relative path for single files
+    e.target.value = '' // allow re-picking the same file
+  }
+
+  const handleDirPick = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const files = Array.from(e.target.files ?? [])
+    addFiles(files, (f) => (f as File & { webkitRelativePath?: string }).webkitRelativePath || f.name)
+    e.target.value = ''
+  }
+
+  // Drag-and-drop handler. We walk the DataTransferItemList recursively
+  // with webkitGetAsEntry so dropped folders contribute every nested
+  // file, with relative paths reconstructed from the entry chain.
+  const handleDrop = async (e: React.DragEvent) => {
+    e.preventDefault()
+    setDragOver(false)
+    const items = Array.from(e.dataTransfer.items)
+    const collected: { file: File; relativePath: string }[] = []
+
+    const walkEntry = (entry: any, pathPrefix: string): Promise<void> => {
+      return new Promise((resolve) => {
+        if (!entry) return resolve()
+        if (entry.isFile) {
+          entry.file((f: File) => {
+            collected.push({
+              file: f,
+              relativePath: pathPrefix ? `${pathPrefix}/${entry.name}` : '',
+            })
+            resolve()
+          }, () => resolve())
+        } else if (entry.isDirectory) {
+          const reader = entry.createReader()
+          const readBatch = () => {
+            reader.readEntries(async (entries: any[]) => {
+              if (!entries.length) return resolve()
+              const childPrefix = pathPrefix ? `${pathPrefix}/${entry.name}` : entry.name
+              await Promise.all(entries.map((c) => walkEntry(c, childPrefix)))
+              // readEntries only returns a batch at a time; loop until empty.
+              readBatch()
+            }, () => resolve())
+          }
+          readBatch()
+        } else {
+          resolve()
+        }
+      })
+    }
+
+    await Promise.all(
+      items.map((it) => {
+        const entry = (it as DataTransferItem & { webkitGetAsEntry?: () => any }).webkitGetAsEntry?.()
+        return walkEntry(entry, '')
+      })
+    )
+
+    if (collected.length === 0) {
+      // Fallback for browsers without webkitGetAsEntry — use plain files.
+      const files = Array.from(e.dataTransfer.files)
+      addFiles(files, (f) => f.name)
+      return
+    }
+
+    const files = collected.map((c) => c.file)
+    const pathMap = new Map<File, string>(collected.map((c) => [c.file, c.relativePath]))
+    addFiles(files, (f) => pathMap.get(f) || f.name)
+  }
+
+  const removeFromQueue = (key: string) => {
+    setQueue((prev) => prev.filter((q) => q.key !== key))
+  }
+
+  const startUpload = async () => {
+    if (!destFolderId || queue.length === 0) return
+    setIsUploading(true)
+    const ctrl = new AbortController()
+    abortRef.current = ctrl
+
+    // Simple worker-pool: up to MAX_PARALLEL concurrent uploads.
+    const pending = queue.filter((q) => q.status === 'pending' || q.status === 'error')
+    let cursor = 0
+    let successCount = 0
+    let failCount = 0
+
+    const uploadOne = async (item: QueuedFile) => {
+      setQueue((prev) =>
+        prev.map((q) => (q.key === item.key ? { ...q, status: 'uploading', progress: 0, error: undefined } : q))
+      )
+      try {
+        await uploads.uploadFile(item.file, destFolderId, {
+          relativePath: item.relativePath || undefined,
+          heapId: destHeapId,
+          signal: ctrl.signal,
+          onProgress: (loaded, total) => {
+            const pct = total > 0 ? loaded / total : 0
+            setQueue((prev) =>
+              prev.map((q) => (q.key === item.key ? { ...q, progress: pct } : q))
+            )
+          },
+        })
+        successCount++
+        setQueue((prev) =>
+          prev.map((q) => (q.key === item.key ? { ...q, status: 'done', progress: 1 } : q))
+        )
+      } catch (err: any) {
+        failCount++
+        const msg = err?.response?.data?.detail || err?.message || 'Upload failed'
+        setQueue((prev) =>
+          prev.map((q) => (q.key === item.key ? { ...q, status: 'error', error: msg } : q))
+        )
+      }
+    }
+
+    const workers: Promise<void>[] = []
+    for (let i = 0; i < Math.min(MAX_PARALLEL, pending.length); i++) {
+      workers.push(
+        (async () => {
+          while (cursor < pending.length && !ctrl.signal.aborted) {
+            const idx = cursor++
+            await uploadOne(pending[idx])
+          }
+        })()
+      )
+    }
+    await Promise.all(workers)
+
+    setIsUploading(false)
+    abortRef.current = null
+
+    // Refresh everything affected by new photos.
+    queryClient.invalidateQueries({ queryKey: FOLDER_TREE_QUERY_KEY })
+    queryClient.invalidateQueries({ queryKey: HEAPS_QUERY_KEY })
+    queryClient.invalidateQueries({ queryKey: LIBRARY_STATS_QUERY_KEY })
+    queryClient.invalidateQueries({ queryKey: ['photos'] })
+
+    if (successCount > 0) {
+      toast.success(
+        `Uploaded ${successCount} file${successCount === 1 ? '' : 's'}`,
+        failCount > 0 ? `${failCount} failed — see list` : undefined
+      )
+    }
+    if (successCount === 0 && failCount > 0) {
+      toast.error('Upload failed', `${failCount} file${failCount === 1 ? '' : 's'} errored`)
+    }
+  }
+
+  const cancelUpload = () => {
+    abortRef.current?.abort()
+  }
+
+  const totalBytes = useMemo(() => queue.reduce((s, q) => s + q.file.size, 0), [queue])
+  const uploadedBytes = useMemo(
+    () => queue.reduce((s, q) => s + q.file.size * (q.status === 'done' ? 1 : q.progress), 0),
+    [queue]
+  )
+  const overallPct = totalBytes > 0 ? Math.round((uploadedBytes / totalBytes) * 100) : 0
+
+  if (!isOpen) return null
+
+  return (
+    <div className="fixed inset-0 z-50">
+      <div
+        className="absolute inset-0 bg-black/60 backdrop-blur-sm"
+        onClick={!isUploading ? onClose : undefined}
+      />
+      <div className="absolute left-1/2 top-1/2 -translate-x-1/2 -translate-y-1/2">
+        <div className="relative z-10 flex max-h-[85vh] w-[760px] flex-col rounded-lg border border-border bg-surface shadow-2xl">
+          {/* Header */}
+          <div className="flex items-center justify-between border-b border-border px-5 py-3">
+            <div className="flex items-center gap-2">
+              <UploadIcon className="h-4 w-4 text-text-muted" />
+              <h2 className="text-base font-semibold text-text">Upload photos</h2>
+            </div>
+            <button
+              onClick={onClose}
+              disabled={isUploading}
+              className="rounded p-1 text-text-muted hover:bg-surface-2 hover:text-text disabled:opacity-40"
+              aria-label="Close"
+            >
+              <X className="h-4 w-4" />
+            </button>
+          </div>
+
+          {/* Body */}
+          <div className="flex min-h-0 flex-1 gap-4 overflow-hidden p-5">
+            {/* Left: destination picker */}
+            <div className="flex w-64 flex-col gap-4 overflow-hidden">
+              <div className="flex flex-col gap-2 overflow-hidden">
+                <label className="text-xs font-medium uppercase tracking-wide text-text-muted">
+                  Destination folder
+                </label>
+                <div className="flex-1 overflow-auto rounded border border-border bg-bg p-1 text-sm">
+                  {folderTree && folderTree.length > 0 ? (
+                    folderTree.map((n) => (
+                      <FolderTreeRow
+                        key={n.id}
+                        node={n}
+                        depth={0}
+                        selectedId={destFolderId}
+                        onSelect={setDestFolderId}
+                        expanded={expandedFolders}
+                        onToggle={(id) =>
+                          setExpandedFolders((prev) => {
+                            const next = new Set(prev)
+                            if (next.has(id)) next.delete(id)
+                            else next.add(id)
+                            return next
+                          })
+                        }
+                      />
+                    ))
+                  ) : (
+                    <div className="p-3 text-xs text-text-muted">No folders yet.</div>
+                  )}
+                </div>
+              </div>
+
+              <div className="flex flex-col gap-2">
+                <label className="text-xs font-medium uppercase tracking-wide text-text-muted">
+                  Also add to heap (optional)
+                </label>
+                <select
+                  value={destHeapId ?? ''}
+                  onChange={(e) => setDestHeapId(e.target.value || null)}
+                  className="rounded border border-border bg-bg px-2 py-1.5 text-sm text-text"
+                >
+                  <option value="">— none —</option>
+                  {allHeaps.map((h) => (
+                    <option key={h.id} value={h.id}>
+                      {h.name}
+                    </option>
+                  ))}
+                </select>
+              </div>
+            </div>
+
+            {/* Right: drop zone + queue */}
+            <div className="flex min-w-0 flex-1 flex-col gap-3 overflow-hidden">
+              <div
+                onDragOver={(e) => {
+                  e.preventDefault()
+                  setDragOver(true)
+                }}
+                onDragLeave={() => setDragOver(false)}
+                onDrop={handleDrop}
+                className={clsx(
+                  'flex flex-col items-center justify-center rounded border-2 border-dashed px-4 py-6 text-center transition-colors',
+                  dragOver
+                    ? 'border-primary bg-primary/10'
+                    : 'border-border bg-bg'
+                )}
+              >
+                <UploadIcon className="mb-2 h-6 w-6 text-text-muted" />
+                <div className="text-sm text-text">
+                  Drop files or folders here
+                </div>
+                <div className="mt-1 text-xs text-text-muted">
+                  Folder structure is preserved under the destination.
+                </div>
+                <div className="mt-3 flex gap-2">
+                  <button
+                    type="button"
+                    onClick={() => fileInputRef.current?.click()}
+                    className="rounded border border-border px-3 py-1 text-xs text-text hover:bg-surface-2"
+                  >
+                    Select files
+                  </button>
+                  <button
+                    type="button"
+                    onClick={() => dirInputRef.current?.click()}
+                    className="rounded border border-border px-3 py-1 text-xs text-text hover:bg-surface-2"
+                  >
+                    Select folder
+                  </button>
+                </div>
+                <input
+                  ref={fileInputRef}
+                  type="file"
+                  multiple
+                  accept="image/*,video/*,.heic,.heif,.cr2,.cr3,.nef,.arw,.raf,.dng,.orf,.rw2,.pef,.srw"
+                  className="hidden"
+                  onChange={handleFilePick}
+                />
+                <input
+                  ref={dirInputRef}
+                  type="file"
+                  multiple
+                  // @ts-expect-error — non-standard but supported in Chromium/WebKit
+                  webkitdirectory=""
+                  directory=""
+                  className="hidden"
+                  onChange={handleDirPick}
+                />
+              </div>
+
+              {/* Queue */}
+              <div className="min-h-0 flex-1 overflow-auto rounded border border-border bg-bg">
+                {queue.length === 0 ? (
+                  <div className="flex h-full items-center justify-center text-xs text-text-muted">
+                    No files added yet.
+                  </div>
+                ) : (
+                  <ul className="divide-y divide-border">
+                    {queue.map((item) => (
+                      <li key={item.key} className="flex items-center gap-2 px-3 py-2 text-sm">
+                        <FileImage className="h-4 w-4 shrink-0 text-text-muted" />
+                        <div className="min-w-0 flex-1">
+                          <div className="truncate text-text">
+                            {item.relativePath || item.file.name}
+                          </div>
+                          {item.status === 'uploading' && (
+                            <div className="mt-1 h-1 w-full overflow-hidden rounded bg-surface-2">
+                              <div
+                                className="h-full bg-primary transition-all"
+                                style={{ width: `${Math.round(item.progress * 100)}%` }}
+                              />
+                            </div>
+                          )}
+                          {item.status === 'error' && item.error && (
+                            <div className="mt-0.5 truncate text-xs text-reject">{item.error}</div>
+                          )}
+                        </div>
+                        <div className="shrink-0">
+                          {item.status === 'done' && <CheckCircle2 className="h-4 w-4 text-green-500" />}
+                          {item.status === 'error' && <AlertCircle className="h-4 w-4 text-reject" />}
+                          {item.status !== 'done' && !isUploading && (
+                            <button
+                              onClick={() => removeFromQueue(item.key)}
+                              className="rounded p-0.5 text-text-muted hover:bg-surface-2 hover:text-text"
+                              aria-label="Remove"
+                            >
+                              <X className="h-3.5 w-3.5" />
+                            </button>
+                          )}
+                        </div>
+                      </li>
+                    ))}
+                  </ul>
+                )}
+              </div>
+
+              {queue.length > 0 && (
+                <div className="text-xs text-text-muted">
+                  {queue.length} file{queue.length === 1 ? '' : 's'} •{' '}
+                  {(totalBytes / 1024 / 1024).toFixed(1)} MB
+                  {isUploading && ` • ${overallPct}% uploaded`}
+                </div>
+              )}
+            </div>
+          </div>
+
+          {/* Footer */}
+          <div className="flex items-center justify-end gap-2 border-t border-border px-5 py-3">
+            <button
+              onClick={isUploading ? cancelUpload : onClose}
+              className="rounded border border-border px-3 py-1.5 text-sm text-text hover:bg-surface-2"
+            >
+              {isUploading ? 'Cancel' : 'Close'}
+            </button>
+            <button
+              onClick={startUpload}
+              disabled={isUploading || queue.length === 0 || !destFolderId}
+              className="flex items-center gap-1.5 rounded bg-primary px-3 py-1.5 text-sm font-medium text-white hover:bg-primary/80 disabled:cursor-not-allowed disabled:opacity-50"
+            >
+              <UploadIcon className="h-3.5 w-3.5" />
+              {isUploading ? 'Uploading…' : `Upload ${queue.length || ''}`.trim()}
+            </button>
+          </div>
+        </div>
+      </div>
+    </div>
+  )
+}
+
+interface FolderTreeRowProps {
+  node: FolderTreeNode
+  depth: number
+  selectedId: string | null
+  onSelect: (id: string) => void
+  expanded: Set<string>
+  onToggle: (id: string) => void
+}
+
+function FolderTreeRow({
+  node,
+  depth,
+  selectedId,
+  onSelect,
+  expanded,
+  onToggle,
+}: FolderTreeRowProps) {
+  const isExpanded = expanded.has(node.id)
+  const hasChildren = node.children && node.children.length > 0
+  const isSelected = selectedId === node.id
+
+  return (
+    <>
+      <div
+        className={clsx(
+          'flex cursor-pointer items-center gap-1 rounded px-1 py-1 text-sm',
+          isSelected ? 'bg-primary/20 text-text' : 'text-text-muted hover:bg-surface-2 hover:text-text'
+        )}
+        style={{ paddingLeft: `${depth * 12 + 4}px` }}
+        onClick={() => onSelect(node.id)}
+      >
+        <button
+          onClick={(e) => {
+            e.stopPropagation()
+            if (hasChildren) onToggle(node.id)
+          }}
+          className="flex h-4 w-4 items-center justify-center"
+          aria-label={isExpanded ? 'Collapse' : 'Expand'}
+        >
+          {hasChildren ? (
+            isExpanded ? (
+              <ChevronDown className="h-3 w-3" />
+            ) : (
+              <ChevronRight className="h-3 w-3" />
+            )
+          ) : null}
+        </button>
+        <FolderIcon className="h-3.5 w-3.5 shrink-0" />
+        <span className="truncate">{node.name}</span>
+      </div>
+      {isExpanded &&
+        node.children?.map((c) => (
+          <FolderTreeRow
+            key={c.id}
+            node={c}
+            depth={depth + 1}
+            selectedId={selectedId}
+            onSelect={onSelect}
+            expanded={expanded}
+            onToggle={onToggle}
+          />
+        ))}
+    </>
+  )
+}
diff --git a/frontend/src/hooks/useFeaturesQuery.ts b/frontend/src/hooks/useFeaturesQuery.ts
new file mode 100644
index 0000000..201ce2d
--- /dev/null
+++ b/frontend/src/hooks/useFeaturesQuery.ts
@@ -0,0 +1,39 @@
+import { useQuery, useQueryClient } from '@tanstack/react-query'
+import { features, type FeaturesMap } from '../services/api'
+
+export const FEATURES_QUERY_KEY = ['features'] as const
+
+/** Read the effective feature-flag state (admin override or YAML
+ *  default). Powers conditional rendering of pipeline-dependent UI —
+ *  People view, Tags view, OCR snippets, etc. */
+export function useFeaturesQuery() {
+  return useQuery<FeaturesMap>({
+    queryKey: FEATURES_QUERY_KEY,
+    queryFn: features.list,
+    // Re-read every minute so admin toggles reflect without a page
+    // reload. The admin tab also invalidates this key on write so the
+    // refresh can be immediate for the admin who just flipped it.
+    staleTime: 60_000,
+    refetchInterval: 60_000,
+  })
+}
+
+export function useIsFeatureEnabled(
+  name:
+    | 'vision.enabled'
+    | 'vision.ocr.enabled'
+    | 'vision.detector.enabled'
+    | 'vision.faces.enabled'
+    | 'vision.classifier.enabled',
+): boolean {
+  const { data } = useFeaturesQuery()
+  // Default to enabled while loading so we don't flash "feature off"
+  // during a first-paint fetch. The backend is the source of truth;
+  // any gated UI that slipped through just returns empty data anyway.
+  if (!data) return true
+  return !!data[name]
+}
+
+export function invalidateFeaturesQuery(queryClient: ReturnType<typeof useQueryClient>) {
+  queryClient.invalidateQueries({ queryKey: FEATURES_QUERY_KEY })
+}
diff --git a/frontend/src/services/api.ts b/frontend/src/services/api.ts
index 5c237f6..0d33764 100644
--- a/frontend/src/services/api.ts
+++ b/frontend/src/services/api.ts
@@ -713,6 +713,72 @@ export const heaps = {
   },
 }
 
+// Upload API — single file per request so the browser can fan out many
+// POSTs in parallel with per-file progress. For folder uploads the
+// caller passes each File's webkitRelativePath so the backend can
+// materialise the folder structure under the destination.
+export const uploads = {
+  uploadFile: async (
+    file: File,
+    destinationFolderId: string,
+    opts: {
+      relativePath?: string
+      heapId?: string | null
+      onProgress?: (loadedBytes: number, totalBytes: number) => void
+      signal?: AbortSignal
+    } = {}
+  ) => {
+    const form = new FormData()
+    form.append('file', file)
+    form.append('destination_folder_id', destinationFolderId)
+    if (opts.relativePath) form.append('relative_path', opts.relativePath)
+    if (opts.heapId) form.append('heap_id', opts.heapId)
+
+    const response = await api.post('/upload', form, {
+      headers: { 'Content-Type': 'multipart/form-data' },
+      signal: opts.signal,
+      onUploadProgress: (evt) => {
+        if (opts.onProgress && evt.total) opts.onProgress(evt.loaded, evt.total)
+      },
+    })
+    return response.data as {
+      photo_id: string
+      filename: string
+      folder_id: string
+      folder_path: string
+      heap_id: string | null
+    }
+  },
+}
+
+// Download helpers — build a URL the browser can pull directly via an
+// <a href>. The backend accepts `?token=` so an <a> works without a
+// custom fetch + save-blob dance; the Authorization header is not
+// settable on a plain link click.
+export const downloads = {
+  folderUrl: (folderId: string): string => {
+    const token = localStorage.getItem('access_token') || ''
+    return `${API_BASE_URL}/download/folders/${folderId}?token=${encodeURIComponent(token)}`
+  },
+  heapUrl: (heapId: string): string => {
+    const token = localStorage.getItem('access_token') || ''
+    return `${API_BASE_URL}/download/heaps/${heapId}?token=${encodeURIComponent(token)}`
+  },
+  trigger: (url: string) => {
+    // Kicking off a download via a transient <a> click keeps the
+    // browser in charge of the file dialog + progress indicator. We
+    // use target=_blank so the current SPA route isn't replaced if
+    // the server returns an error mid-stream.
+    const a = document.createElement('a')
+    a.href = url
+    a.rel = 'noopener'
+    a.target = '_blank'
+    document.body.appendChild(a)
+    a.click()
+    document.body.removeChild(a)
+  },
+}
+
 // Sharing API
 
 export interface SharedHeap {
@@ -928,6 +994,61 @@ export const admin = {
     const response = await api.delete(`/admin/users/${userId}`)
     return response.data
   },
+
+  // --- AI / vision feature flags + manual pipeline triggers -----------
+
+  listFeatureFlags: async (): Promise<{ flags: FeatureFlagSnapshot }> => {
+    const response = await api.get('/admin/feature-flags')
+    return response.data
+  },
+
+  /** Set ``value`` to toggle; pass ``null`` to clear the override and
+   *  fall back to the YAML default. */
+  setFeatureFlag: async (
+    name: string,
+    value: boolean | null,
+  ): Promise<{ flags: FeatureFlagSnapshot }> => {
+    const response = await api.patch(`/admin/feature-flags/${encodeURIComponent(name)}`, { value })
+    return response.data
+  },
+
+  triggerAiBackfill: async (body: {
+    task?: 'embed' | 'ocr' | 'detect' | 'faces' | 'classify' | null
+    limit?: number | null
+  }): Promise<{ status: string; task_id: string }> => {
+    const response = await api.post('/admin/ai/backfill', body)
+    return response.data
+  },
+
+  triggerFaceRecluster: async (): Promise<{ status: string; task_id: string }> => {
+    const response = await api.post('/admin/ai/recluster-faces')
+    return response.data
+  },
+
+  triggerFullRescan: async (): Promise<{ status: string; task_id: string }> => {
+    const response = await api.post('/admin/ai/rescan')
+    return response.data
+  },
+}
+
+export interface FeatureFlagState {
+  effective: boolean
+  default: boolean
+  overridden: boolean
+}
+
+export type FeatureFlagSnapshot = Record<string, FeatureFlagState>
+
+export type FeaturesMap = Record<string, boolean>
+
+// Public read of effective feature flags. Available to any signed-in
+// user so the frontend can hide sections that depend on a disabled
+// pipeline stage (e.g. People when faces are off).
+export const features = {
+  list: async (): Promise<FeaturesMap> => {
+    const response = await api.get('/features')
+    return response.data
+  },
 }
 
 export default api
\ No newline at end of file