fix: assorted UI polish from review pass

- FilterPill: drop the inline value text from the active state. Pills
  now stay the same width whether or not a filter is set; the popover
  is the canonical place to read the value, and the title attribute
  surfaces it on hover.
- TopBar: remove the search input — search lives in the filter bar now.
- FilterBar: add a search input on the left, with the pill cluster
  centered between it and a flex-shrink-0 Clear-all on the right.
- LeftSidebar / HeapsPanel: count badges use a fixed-width slot
  (h-5 min-w-[24px], tabular-nums) so counts line up in the same
  visual column across rows. Empty rows reserve the slot.
- LeftSidebar: pull section counts (All Photos, Rated, Duplicates,
  Discarded) from a new useLibraryStatsQuery hook backed by the
  expanded /library/stats endpoint. Tags count was already wired.
- backend/library: stats endpoint returns per-section counts that
  match the filter the sidebar applies on click.
- Stats invalidation hooked into the standard photo-mutation paths.
- RightSidebar header: h-12 to match TopBar height.
- Timeline sticky date overlay: only show once the natural in-grid
  header has scrolled OUT of the viewport. Avoids the duplicate-label
  flash when both labels would be visible.

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

backend/app/routers/library.py

@@ -12,30 +12,68 @@ router = APIRouter()
 
 @router.get("/stats")
 async def get_library_stats(db: AsyncSession = Depends(get_db)):
-    """Get library statistics"""
-    # Count total photos
-    total_photos = await db.execute(
-        select(func.count(Photo.id)).where(Photo.media_type.in_(['photo', 'heic', 'raw']))
-    )
-    photo_count = total_photos.scalar()
-    
-    # Count total videos
-    total_videos = await db.execute(
-        select(func.count(Photo.id)).where(Photo.media_type == 'video')
-    )
-    video_count = total_videos.scalar()
-    
-    # Calculate total size
-    total_size = await db.execute(
-        select(func.sum(Photo.file_size))
-    )
-    size = total_size.scalar() or 0
-    
+    """Get library statistics + per-section counts. Each section count
+    matches the filter the sidebar applies when you click it, so the
+    sidebar badges and the timeline below them stay in sync.
+
+      - all_photos:   non-discarded photos + videos (matches the All
+                      Photos section's default filter)
+      - rated:        non-discarded with rating >= 1
+      - duplicates:   non-discarded with is_duplicate = true
+      - discarded:    is_discarded = true
+      - total_size:   raw bytes across every row, including discarded
+    """
+    not_discarded = Photo.is_discarded.is_(False)
+
+    all_photos_count = (
+        await db.execute(select(func.count(Photo.id)).where(not_discarded))
+    ).scalar() or 0
+
+    rated_count = (
+        await db.execute(
+            select(func.count(Photo.id)).where(not_discarded, Photo.rating >= 1)
+        )
+    ).scalar() or 0
+
+    duplicates_count = (
+        await db.execute(
+            select(func.count(Photo.id)).where(
+                not_discarded, Photo.is_duplicate.is_(True)
+            )
+        )
+    ).scalar() or 0
+
+    discarded_count = (
+        await db.execute(
+            select(func.count(Photo.id)).where(Photo.is_discarded.is_(True))
+        )
+    ).scalar() or 0
+
+    # Legacy split (kept for the existing /stats consumers).
+    photo_count = (
+        await db.execute(
+            select(func.count(Photo.id)).where(
+                Photo.media_type.in_(['photo', 'heic', 'raw'])
+            )
+        )
+    ).scalar() or 0
+    video_count = (
+        await db.execute(
+            select(func.count(Photo.id)).where(Photo.media_type == 'video')
+        )
+    ).scalar() or 0
+
+    size = (await db.execute(select(func.sum(Photo.file_size)))).scalar() or 0
+
     return {
+        "all_photos": all_photos_count,
+        "rated": rated_count,
+        "duplicates": duplicates_count,
+        "discarded": discarded_count,
         "total_photos": photo_count,
         "total_videos": video_count,
         "total_size": size,
-        "total_size_gb": round(size / (1024**3), 2) if size else 0
+        "total_size_gb": round(size / (1024**3), 2) if size else 0,
     }
 
 @router.post("/scan")