feat: directory scanner plugin — walk library paths, auto-register assets

- DirectoryScannerPlugin: recursive directory walk via FileStoragePort
- Computes SHA256 checksums, classifies media by extension
- Registers each file via RegisterAssetHandler (triggers AssetIngested → extract_metadata pipeline)
- Reads library_path_id from job payload, looks up volume + path
- Seeded plugin + scan_directory pipeline
- Trigger via POST /jobs with { job_type: "ScanDirectory", payload: { library_path_id: "..." } }

k-photos-frontend/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "k-photos-frontend",
+  "version": "0.0.1",
+  "type": "module",
+  "private": true,
+  "scripts": {
+    "dev": "next dev",
+    "build": "next build",
+    "start": "next start",
+    "lint": "eslint",
+    "format": "prettier --write \"**/*.{ts,tsx}\"",
+    "typecheck": "tsc --noEmit"
+  },
+  "dependencies": {
+    "next": "16.2.6",
+    "next-themes": "^0.4.6",
+    "react": "19.2.4",
+    "react-dom": "19.2.4"
+  },
+  "devDependencies": {
+    "@tailwindcss/postcss": "^4",
+    "@types/node": "^20",
+    "@types/react": "^19",
+    "@types/react-dom": "^19",
+    "eslint": "^9",
+    "eslint-config-next": "16.2.6",
+    "prettier": "^3.8.3",
+    "prettier-plugin-tailwindcss": "^0.8.0",
+    "tailwindcss": "^4",
+    "typescript": "^5"
+  }
+}