Add NextGen library: index DB, thumbnails, AI culling, and CLIP search

Builds the "indexed library" foundation and first intelligent features on
top of the organizer (sql.js index, non-destructive in-place indexing).

Phase 0 — Library index:
- sql.js (WASM SQLite) index DB; contentHash-keyed assets, resumable indexing
  (skip by path+mtime), batch persistence (chosen over native better-sqlite3
  which fails to build on Node 24 / Python 3.12)
- Library folders (in place, non-destructive) + background indexer w/ progress
- Thumbnails generated in the AI worker (canvas->webp), cached in userData;
  served via photoai-media://thumb by hash; thumbnail grid w/ pagination

Phase 1 — AI quality assessment & culling:
- Focus (Laplacian variance), exposure (histogram), eyes-open (face-api EAR)
  computed in one analyze pass alongside the thumbnail
- Culling filters (candidate/rejected) + quality badges
- Adjustable thresholds (live SQL re-classification from stored raw scores,
  no re-analysis) + manual star rating (0-5) and color labels (usermeta)

Phase 2 — CLIP natural-language / similarity search:
- @huggingface/transformers (WASM/WebGPU, no native build)
- CLIP image/text embeddings (lazy-loaded); Korean queries auto-translated
  via opus-mt-ko-en into the English CLIP
- Embeddings stored as SQLite BLOBs; "build search index" batch w/ progress;
  brute-force cosine search; new Search tab
- Note: models download from HF Hub on first use; fully-offline ORT-wasm
  packaging and KO search-accuracy tuning are follow-ups

Tabs added (Organize / Library / Search). All typecheck/tests(12)/build green;
boot smoke verified across phases.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

package.json

@@ -22,14 +22,17 @@
     "dist:all": "electron-vite build && electron-builder --win --mac"
   },
   "dependencies": {
+    "@huggingface/transformers": "^3.8.1",
     "@vladmandic/face-api": "^1.7.13",
     "exifr": "^7.1.3",
+    "sql.js": "^1.12.0",
     "zustand": "^4.5.5"
   },
   "devDependencies": {
     "@types/node": "^20.16.0",
     "@types/react": "^18.3.5",
     "@types/react-dom": "^18.3.0",
+    "@types/sql.js": "^1.4.9",
     "@vitejs/plugin-react": "^4.3.1",
     "autoprefixer": "^10.4.20",
     "electron": "^33.0.0",