Simplify auth, remove abstraction layers, add shadcn components

- Delete lib/api/errors.ts and lib/api/auth-guard.ts, inline
  NextResponse.json() error responses directly in route handlers
- Replace non-standard amber CSS variables with primary/primary-foreground
- Regenerate shadcn UI components with biome-ignore comments
- Add CLAUDE.md for repository guidance
- Update dependencies and pnpm lockfile

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

package.json

@@ -20,14 +20,22 @@
     "better-sqlite3": "^12.6.2",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "cmdk": "^1.1.1",
+    "date-fns": "^4.1.0",
     "drizzle-orm": "^0.45.1",
+    "embla-carousel-react": "^8.6.0",
     "next": "16.1.6",
     "react": "19.2.4",
+    "react-day-picker": "^9.14.0",
     "react-dom": "19.2.4",
+    "react-resizable-panels": "^4.6.5",
+    "recharts": "2.15.4",
     "shadcn": "^3.8.5",
+    "sonner": "^2.0.7",
     "tailwind-merge": "^3.5.0",
     "tw-animate-css": "^1.4.0",
-    "uuid": "^13.0.0"
+    "uuid": "^13.0.0",
+    "vaul": "^1.1.2"
   },
   "devDependencies": {
     "@biomejs/biome": "2.4.4",
@@ -36,16 +44,9 @@
     "@types/node": "^25.3.2",
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
-    "@types/uuid": "^11.0.0",
     "babel-plugin-react-compiler": "1.0.0",
     "drizzle-kit": "^0.31.9",
     "tailwindcss": "^4.2.1",
     "typescript": "^5.9.3"
-  },
-  "pnpm": {
-    "onlyBuiltDependencies": [
-      "better-sqlite3",
-      "esbuild"
-    ]
   }
 }