refactor: rename trash to discard end-to-end

User-facing labels and code now use "discard" (verb) and "Discarded"
(state/view label) instead of "trash" / "Trashed". The DB column names
stay (is_trashed / trashed_at) so no migration is required — only the
SQLAlchemy attribute names are renamed via Column('old_name', ...).

Backend
- Photo model: is_discarded / discarded_at attributes (DB columns
  unchanged).
- PhotoBase / PhotoResponse / PhotoUpdate schemas use the new field
  names.
- Photos list endpoint: is_discarded query param, filter logic.
- DELETE /photos/{id} now sets is_discarded; success message updated.
- Bulk action 'trash' renamed to 'discard'.
- backend/app/routers/trash.py renamed to discard.py with renamed
  functions and route prefix /api/v1/discard.
- main.py imports and mounts the discard router.
- tasks/scan.py marks missing files as is_discarded.

Frontend
- Photo TS type: is_discarded.
- PhotoThumbnail: shows the trash-can icon when is_discarded.
- RightSidebar: button label "Discard"; mutation field name; local
  variable rename.
- TopBar: discardPhotosMutation and "Discard" button; toast text
  "Discarded".
- LeftSidebar: virtual node id 'discarded' / label "Discarded".
- FilterBar / filterStore / useFilterUrlSync: FlagFilter enum value
  'trashed' → 'discarded'; backend param key is_discarded.
- KeyboardHints: X label "Discard".
- useKeyboardShortcuts: PhotoUpdate field rename, X handler.
- api.ts: /trash routes → /discard, trash export → discard,
  bulkUpdate trash field → discard.

Out of scope (intentional): the docker-compose trash_data volume,
backend/Dockerfile mkdir /data/trash, config.py TrashSettings, and
the spec doc — all unused since soft-discard, and renaming them is
churn for no benefit.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/routers/discard.py

@@ -1,5 +1,5 @@
 """
-Trash API router
+Discard API router
 """
 from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy import select, and_
@@ -12,39 +12,39 @@ from app.models import Photo
 router = APIRouter()
 
 @router.get("")
-async def list_trashed(db: AsyncSession = Depends(get_db)):
-    """List trashed photos"""
+async def list_discarded(db: AsyncSession = Depends(get_db)):
+    """List discarded photos"""
     result = await db.execute(
-        select(Photo).where(Photo.is_trashed == True)
+        select(Photo).where(Photo.is_discarded == True)
     )
     photos = result.scalars().all()
     return photos
 
 @router.post("/restore")
 async def restore_photos(photo_ids: list[str], db: AsyncSession = Depends(get_db)):
-    """Restore photos from trash"""
+    """Restore photos from the discard pile"""
     result = await db.execute(
-        select(Photo).where(and_(Photo.id.in_(photo_ids), Photo.is_trashed == True))
+        select(Photo).where(and_(Photo.id.in_(photo_ids), Photo.is_discarded == True))
     )
     photos = result.scalars().all()
-    
+
     for photo in photos:
-        photo.is_trashed = False
-        photo.trashed_at = None
-    
+        photo.is_discarded = False
+        photo.discarded_at = None
+
     await db.commit()
     return {"status": "success", "restored": len(photos)}
 
 @router.delete("/empty")
-async def empty_trash(db: AsyncSession = Depends(get_db)):
-    """Permanently delete all trashed photos"""
+async def empty_discard(db: AsyncSession = Depends(get_db)):
+    """Permanently delete all discarded photos"""
     result = await db.execute(
-        select(Photo).where(Photo.is_trashed == True)
+        select(Photo).where(Photo.is_discarded == True)
     )
     photos = result.scalars().all()
-    
+
     for photo in photos:
         await db.delete(photo)
-    
+
     await db.commit()
-    return {"status": "success", "deleted": len(photos)}
+    return {"status": "success", "deleted": len(photos)}

backend/app/routers/photos.py

@@ -33,7 +33,7 @@ async def list_photos(
     rating_max: Optional[int] = Query(None, ge=0, le=5),
     color_label: Optional[str] = None,
     is_picked: Optional[bool] = None,
-    is_trashed: Optional[bool] = False,
+    is_discarded: Optional[bool] = False,
     heap_id: Optional[str] = None,
     sort: str = "taken_at",
     order: str = "desc",
@@ -93,8 +93,8 @@ async def list_photos(
     if is_picked is not None:
         filters.append(Photo.is_picked == is_picked)
 
-    # Trash filter — defaults to hiding trashed photos
-    filters.append(Photo.is_trashed == is_trashed)
+    # Discard filter — defaults to hiding discarded photos
+    filters.append(Photo.is_discarded == is_discarded)
     
     # Apply all filters
     if filters:
@@ -407,13 +407,13 @@ async def update_photo(
     return PhotoResponse.from_orm(photo)
 
 @router.delete("/{photo_id}")
-async def trash_photo(
+async def discard_photo(
     photo_id: str,
     db: AsyncSession = Depends(get_db)
 ):
-    """Soft-trash a photo: sets is_trashed=true. The file stays on disk so
+    """Soft-discard a photo: sets is_discarded=true. The file stays on disk so
     restore is just a flag flip. Permanent deletion happens via DELETE
-    /trash/{id} or DELETE /trash/empty.
+    /discard/{id} or DELETE /discard/empty.
     """
     result = await db.execute(
         select(Photo).where(Photo.id == photo_id)
@@ -423,11 +423,11 @@ async def trash_photo(
     if not photo:
         raise HTTPException(status_code=404, detail="Photo not found")
 
-    photo.is_trashed = True
-    photo.trashed_at = datetime.utcnow()
+    photo.is_discarded = True
+    photo.discarded_at = datetime.utcnow()
     await db.commit()
 
-    return {"status": "success", "message": "Photo moved to trash"}
+    return {"status": "success", "message": "Photo discarded"}
 
 @router.post("/bulk")
 async def bulk_action(
@@ -445,14 +445,14 @@ async def bulk_action(
         raise HTTPException(status_code=404, detail="No photos found")
     
     # Perform action based on type
-    if action.action == 'trash':
+    if action.action == 'discard':
         for photo in photos:
-            photo.is_trashed = True
-            photo.trashed_at = datetime.utcnow()
+            photo.is_discarded = True
+            photo.discarded_at = datetime.utcnow()
     elif action.action == 'restore':
         for photo in photos:
-            photo.is_trashed = False
-            photo.trashed_at = None
+            photo.is_discarded = False
+            photo.discarded_at = None
     elif action.action == 'set_rating':
         for photo in photos:
             photo.rating = action.value
@@ -462,7 +462,7 @@ async def bulk_action(
     elif action.action == 'pick':
         for photo in photos:
             photo.is_picked = True
-            photo.is_trashed = False
+            photo.is_discarded = False
     else:
         raise HTTPException(status_code=400, detail="Invalid action")