feat(infra): add tools service with document scanner, image & PDF tools

Implement self-hosted document scanner and media processing tools as
an alternative to CamScanner/ilovepdf without third-party uploads.

Backend: Rust Axum gateway + worker pool with NATS JetStream queue
Frontend: Next.js 16 + shadcn/ui + Tailwind v4 + Framer Motion
Pipeline: Canny edge detection -> DLT homography warp -> Sauvola
binarization -> Hough deskew -> Tesseract OCR -> searchable PDF

Phase 1 (MVP) delivers:
- Document scanner with perspective correction and OCR
- Image compress/resize/convert tools
- PDF merge/split/compress tools
- Real-time WebSocket progress updates
- Rate limiting, auto-cleanup, Prometheus metrics
- Full CI/CD pipeline with Docker multi-stage build

Co-Authored-By: Kilo <kilo@kilo.ai>

apps/tools/frontend/public/manifest.json

@@ -0,0 +1,13 @@
+{
+  "name": "Tools — Asep Haryana",
+  "short_name": "Tools",
+  "description": "Document Scanner, Image & PDF Tools",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#0a0a1a",
+  "theme_color": "#0a0a1a",
+  "icons": [
+    { "src": "/icons/icon-192.png", "sizes": "192x192", "type": "image/png" },
+    { "src": "/icons/icon-512.png", "sizes": "512x512", "type": "image/png" }
+  ]
+}