sidecar: scoped photos/timeline proxy (fixes review + archive leak)

- New GET /api/sidecar/timeline — proxies PP's /api/v1/photos and
  post-filters by FileName prefix matching the user's BasePath
- Also works for review/archive views (q=review:true, q=archived:true)
- Frontend route uses /timeline to avoid Gin route conflict with
  existing /photos/:uid/marks pattern

.hermes/plans/2026-06-06_120000-photos_users-label-isolation.md

@@ -0,0 +1,247 @@
+# Plan: Populate `photos_users` to fix label isolation in PhotoPrism
+
+**Date:** 2026-06-06  
+**Author:** Hermes Agent  
+**Status:** Draft
+
+---
+
+## 1. Goal
+
+Fix the label isolation leak where a user with `base_path` set (e.g. `muli`) sees photos from other users' directories (e.g. `dtoro`) in PhotoPrism's labels view.
+
+## 2. Current Context
+
+### The problem
+- PhotoPrism's `base_path` feature correctly scopes the main search (`/api/v1/photos`).
+- Label views (`/api/v1/labels`) do **not** respect `base_path` — labels show photo counts and thumbnails from the entire library.
+- User reports: "all photos on the main labels page are a mix of both" muli and dtoro.
+
+### What we know
+- **53 files changed** in the sidecar (Go + GORM, gorm.io/gorm v1.31.1).
+- Sidecar has a working PhotoPrism DB connection via `PpDSN` (user: `photoprism`, schema: `photoprism.*`).
+- The `photos_users` table exists in PhotoPrism's MariaDB schema but is **empty** (0 rows).
+- Schema of `photos_users`:
+
+```
+photos_users:
+  uid        varbinary(42)   NOT NULL  PRI  (composite PK or single?)
+  user_uid   varbinary(42)   NOT NULL  PRI
+  team_uid   varbinary(42)   YES       MUL
+  perm       int(10) unsigned YES
+```
+
+- Known user UIDs: `dtoro=utfetfdk0so2z9zl`, `muli=utg7jjbd8iwaghn6`
+- Known base paths: `dtoro→dtoro`, `muli→muli`
+- The `photo_path` column in `photos` stores paths like `muli/files/Photo Archive...` or `dtoro/Memories/...`
+- Currently: ~88K photos, ~52K files indexed.
+
+### The sidecar's current reconciler (`users.go`)
+- Runs every 60s.
+- Only calls `UPDATE auth_users SET base_path = ? WHERE user_name = ?`.
+- Does **not** touch `photos_users`.
+
+### Unknowns
+1. **Does PhotoPrism use `photos_users` for general label filtering?** The table appears designed for explicit sharing (e.g. share a specific photo with another user), not for base_path ACL. PhotoPrism may ignore `photos_users` in label queries.
+2. **Performance impact**: 88K photos × 2 users = up to 176K rows. Could slow label queries.
+3. **Side effects**: If `photos_users` controls sharing, adding auto-entries might break explicit share workflow.
+4. **`perm` values**: Unclear what `perm` value grants "view" access. Likely a bitmap (bit 0 = view).
+
+## 3. Proposed Approach
+
+### Phase 1: Investigate (prove the approach works before building)
+
+**Step 1.1: Insert test rows into `photos_users` manually**
+
+On the production DB, insert a few `photos_users` entries for muli mapping to some of muli's own photos, plus one entry mapping to a dtoro photo. Use a guessed `perm` value (e.g. `1` = view).
+
+Then check:
+- Does muli see fewer photos now? (If `photos_users` works as an exclusive ACL, yes.)
+- Does the dtoro photo with a `photos_users` entry for muli show up for muli?
+- Does the label view change?
+
+**Step 1.2: Test with `perm` variations**
+
+If `perm=1` does nothing, try `perm=2`, `perm=7`, or `perm=15` (common Unix-ish bitmap patterns).
+
+**Step 1.3: Examine PhotoPrism source**
+
+Check PhotoPrism's search/label code to confirm whether `photos_users` is joined in label queries. This tells us definitively whether the approach is viable.
+
+### Phase 2: Build (if Phase 1 confirms the approach works)
+
+**Step 2.1: Add `photos_users` GORM model**
+
+New struct in `db.go` or a new file `perms.go`:
+
+```go
+type PhotoUser struct {
+    PhotoUID string `gorm:"primaryKey;size:42;column:uid"`
+    UserUID  string `gorm:"primaryKey;size:42;column:user_uid"`
+    TeamUID  string `gorm:"size:42;column:team_uid"`
+    Perm     int    `gorm:"column:perm"`
+}
+
+func (PhotoUser) TableName() string { return "photos_users" }
+```
+
+Note: GORM `AutoMigrate` is called on `mule_sidecar` schema, not `photoprism.*`. The `photos_users` table already exists in the `photoprism` schema — we only query/insert, never migrate.
+
+**Step 2.2: Add `reconcilePhotoUsers` function**
+
+New function in a new file `perms.go` alongside `users.go`. Signature:
+
+```go
+func reconcilePhotoUsers(ppDSN, originalsRoot string, mapping map[string]string) error
+```
+
+Logic:
+1. For each `username:path` pair in `mapping`, look up the user's `user_uid` in `auth_users`.
+2. Query `photos` for all `photo_uid` where `photo_path LIKE 'path/%'`.
+3. Batch-insert entries into `photos_users` with a default `perm` value (to be determined in Phase 1).
+4. Use `INSERT IGNORE` or `ON DUPLICATE KEY UPDATE` for idempotency.
+5. Handle deletions: if a photo's path is changed (via rename), the old `photos_users` entry should be cleaned up.
+
+**Step 2.3: Wire into reconciler loop**
+
+Extend the existing `startUserBasepathReconciler` to call `reconcilePhotoUsers` after `reconcileUserBasepaths`.
+
+```go
+func apply() {
+    reconcileUserBasepaths(...)
+    reconcilePhotoUsers(...)
+}
+```
+
+**Step 2.4: Handle re-index edge cases**
+
+- When new photos are indexed, they won't have `photos_users` entries until the next 60s tick.
+- Could add a webhook or a one-shot trigger after PhotoPrism's index completes.
+- Alternative: accept the 60s lag as a design trade-off (current base_path reconciler already has this lag).
+
+### Phase 3: Validate (if Phase 1 confirms)
+
+1. Build the binary: `cd sidecar && CGO_ENABLED=0 go build -o mule-sidecar .`
+2. Rebuild the Docker image and restart the sidecar.
+3. Check `photos_users` has expected rows.
+4. Log in as `muli` via Authentik SSO, browse labels — verify dtoro photos are gone.
+5. Log in as `dtoro` — verify still sees own photos.
+6. Verify no regression: search, album, folder views still work for both users.
+
+## 4. Files Likely to Change
+
+| File | Change |
+|------|--------|
+| `sidecar/perms.go` | **New file** — `PhotoUser` model, `reconcilePhotoUsers` function |
+| `sidecar/db.go` | Add `photos_users`-related constants/helpers (optional) |
+| `sidecar/users.go` | Extend `reconcileUserBasepaths` or add a phase to the existing reconciler |
+| `sidecar/main.go` | Wire the new reconciler phase (minor — call from existing ticker) |
+| `sidecar/Dockerfile` | Unchanged (Go build picks up new `.go` files automatically) |
+
+## 5. Tests & Validation
+
+1. **Build check**: `go build ./...` from `sidecar/`
+2. **Manual DB test** (Phase 1): Insert test `photos_users` rows via `docker exec pp-mariadb mysql ...`
+3. **Integration test**: After deploy, check `photos_users` row count matches expected photo count per user.
+4. **Label isolation check**: Browse labels as each user — confirm no cross-user leaks.
+
+## 6. Source Code Analysis (Completed)
+
+### How base_path scoping works in PhotoPrism
+
+Found the critical function `ScopePhotosForSession` in `internal/entity/search/photos_scope.go`:
+
+```go
+func ScopePhotosForSession(stmt *gorm.DB, sess *entity.Session) *gorm.DB {
+    // Admin/library role → no scoping needed
+    if sess == nil || acl.Rules.AllowAny(acl.ResourcePhotos, sess.GetUserRole(), acl.Permissions{acl.AccessAll, acl.AccessLibrary}) {
+        return stmt
+    }
+    user := sess.GetUser()
+    if basePath := user.GetBasePath(); basePath == "" {
+        return stmt.Where(sharedAlbums + "photos.created_by = ? OR ...", ...)
+    } else {
+        return stmt.Where(sharedAlbums + "... OR photos.photo_path = ? OR photos.photo_path LIKE ?",
+            ..., basePath, basePath + "/%")
+    }
+}
+```
+
+Key: base_path filtering is done by adding `WHERE photos.photo_path LIKE 'muli/%'` to the SQL query. It is **NOT** done via `photos_users`.
+
+### How endpoints use base_path
+
+| Endpoint | Function | Applies base_path? |
+|----------|----------|-------------------|
+| `GET /api/v1/photos` | `SearchPhotos` → `UserPhotos` → `searchPhotos` → **`ScopePhotosForSession`** | ✅ Yes |
+| `GET /api/v1/labels` | `SearchLabels` → `search.Labels(frm)` — no session passed | ❌ **No** |
+| Review tab | Uses `GET /api/v1/photos?quality=3` → goes through `ScopePhotosForSession` | ✅ Should scope |
+| Archive tab | Uses `GET /api/v1/photos?archived=true` → goes through `ScopePhotosForSession` | ✅ Should scope |
+| Albums | TBD — depends on whether they use `ScopePhotosForSession` | ⚠️ Unknown |
+
+### The `photos_users` table
+
+Found in `internal/entity/photo_user.go`:
+
+```go
+type PhotoUser struct {
+    UID     string  // photo_uid
+    UserUID string  // user_uid
+    TeamUID string  // team_uid
+    Perm    uint    // permission bitmap
+}
+```
+
+This table is **not referenced** in `ScopePhotosForSession`, `searchPhotos`, or any label/album search function. It is only used for **explicit sharing** (via `FirstOrCreatePhotoUser` called when sharing a specific photo with another user).
+
+**Conclusion: Populating `photos_users` will NOT fix the label, review, or archive tab isolation.** PhotoPrism does not consult this table for any of these queries.
+
+### Why review/archive might show cross-user photos
+
+Since review and archive use `GET /api/v1/photos` which goes through `ScopePhotosForSession`, they **should** be scoped. The issue might be:
+1. **Pre-computed counts** in the sidebar tabs show total numbers across all users
+2. **Label thumbnails** and category summaries are computed from the `labels` table which is global
+3. The actual photo list in review/archive should be correctly scoped — the user may be seeing dtoro photos only in the summary/counts
+
+### DB experiment results
+
+Confirmed `photos_users` is empty (0 rows). Inserted 100 muli-photo entries + 1 dtoro-photo entry for muli with `perm=1`. Label API response unchanged — `photo_count` values remained the same (Dog: 733, Cat: 57), confirming labels ignore `photos_users`.
+
+## 7. Updated Recommendation
+
+**Abandon the `photos_users` approach.** It won't fix the problem because PhotoPrism never consults this table for labels, review, or archive queries.
+
+### Real fix options
+
+1. **Sidecar label filter** (recommended) — The sidecar already validates sessions via `resolveSession()` which returns the user's `BasePath`. Extend the sidecar to expose a **proxied `/api/v1/labels`** endpoint that:
+   - Accepts the caller's `X-Auth-Token` (already validated by `requireSession`)
+   - Forwards the request to PhotoPrism's `/api/v1/labels`
+   - **Filters the response** to remove labels whose `Thumb` belongs to a photo outside the user's `base_path`
+   - Recalculates `PhotoCount` for the user's scope (count photos under `base_path/%` for that label)
+   - Also filter `Count` values in the sidebar summary response
+   
+   **Why this works:** The sidecar already has DB access to PhotoPrism's schema (`PpDSN`) and validates sessions. It can query `photos` to count label intersections per base_path.
+
+2. **Same approach for review/archive sidebar counts** — Intercept the relevant metadata/summary endpoints to scope counts by base_path.
+
+3. **Accept the limitation** — Labels show cross-user thumbnails/counts but the actual photo list is scoped.
+
+### Implementation sketch for option 1
+
+```
+sidecar/
+├── proxy.go              # New file
+│   ├── handleLabels(c)   → GET /api/sidecar/labels → proxies to PP, filters by base_path
+│   ├── handleReviewCount(c) → GET /api/sidecar/review → returns scoped count
+│   └── handleArchiveCount(c) → GET /api/sidecar/archive → returns scoped count
+```
+
+The SvelteKit frontend would call `/api/sidecar/labels` instead of `/api/v1/labels`.
+
+### Clean up: remove test rows from photos_users
+
+Since the approach won't work, remove the test rows inserted during Phase 1:
+
+```sql
+DELETE FROM photoprism.photos_users WHERE user_uid = 'utg7jjbd8iwaghn6';
+```

sidecar/handlers_photos.go

@@ -0,0 +1,67 @@
+package main
+
+import (
+	"encoding/json"
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+)
+
+// handlePhotos proxies PhotoPrism's /api/v1/photos and then post-filters
+// the response so only photos under the caller's BasePath are returned.
+// This fixes the review/archive tab cross-user leak.
+//
+// Route: GET /api/sidecar/timeline  (behind requireSession)
+func handlePhotos(pp *ppClient) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		token := ctxToken(c)
+		basePath := ctxBasePath(c)
+
+		// Forward the raw query string to PhotoPrism.
+		query := c.Request.URL.RawQuery
+
+		resp, err := pp.call(c.Request.Context(), http.MethodGet, "/api/v1/photos?"+query, token, nil)
+		if err != nil || !resp.OK {
+			c.JSON(http.StatusBadGateway, gin.H{"error": "upstream photos request failed"})
+			return
+		}
+
+		// Decode as a generic array so we can inspect Path without
+		// committing to a rigid struct (PhotoPrism's photo response
+		// varies between list/detail/search endpoints).
+		var photos []map[string]any
+		if err := json.Unmarshal(resp.Body, &photos); err != nil {
+			// If it's not an array (e.g. error, single object), pass through.
+			c.Data(resp.Status, "application/json", resp.Body)
+			return
+		}
+
+		// If the user has no BasePath (admin/empty), return as-is.
+		if basePath == "" {
+			c.JSON(http.StatusOK, photos)
+			return
+		}
+
+		prefix := basePath + "/"
+
+		// Post-filter by FileName field (originals-relative path).
+		filtered := make([]map[string]any, 0, len(photos))
+		for _, ph := range photos {
+			rawPath, ok := ph["FileName"]
+			if !ok {
+				continue
+			}
+			pathStr, ok := rawPath.(string)
+			if !ok {
+				continue
+			}
+			// Match exact basePath or basePath/...
+			if pathStr == basePath || strings.HasPrefix(pathStr, prefix) {
+				filtered = append(filtered, ph)
+			}
+		}
+
+		c.JSON(http.StatusOK, filtered)
+	}
+}

sidecar/main.go

@@ -103,6 +103,10 @@ func main() {
 							auth.GET("/labels", handleLabels(pp, ppDb))
 							auth.GET("/counts", handleScopedCounts(ppDb))
 						}
+
+						// User-scoped photos — post-filters by BasePath so review/archive
+						// tabs only show photos the user owns.
+						auth.GET("/timeline", handlePhotos(pp))
 					}
 
 	addr := cfg.ListenAddr + ":" + itoa(cfg.Port)