feat(FN-003): add tool manifest registry with FastAPI CRUD and built-in manifests

- Add ToolManifest Pydantic models with validators for ports, mounts, health checks, and traefik config

- Implement in-memory ToolRegistry with YAML loading and built-in manifest scanning

- Add FastAPI CRUD routes for listing, retrieving, and creating tool manifests

- Include built-in manifests for runfusion and code-server

- Harden web Dockerfile with unprivileged nginx and port 8080

- Add tool manifest specification documentation and architecture updates

Fusion-Task-Id: FN-003

apps/web/nginx.conf

@@ -1,5 +1,5 @@
 server {
-    listen 80;
+    listen 8080;
     server_name localhost;
     root /usr/share/nginx/html;
     index index.html;
@@ -14,6 +14,8 @@ server {
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection 'upgrade';
         proxy_set_header Host $host;
+        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+        proxy_set_header X-Forwarded-Proto $scheme;
         proxy_cache_bypass $http_upgrade;
     }
 }