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/Dockerfile

@@ -9,9 +9,9 @@ RUN npm install -g pnpm@11.1.1 \
 COPY . .
 RUN pnpm build
 
-FROM nginx:alpine
+FROM nginxinc/nginx-unprivileged:alpine
 
 COPY --from=builder /app/dist /usr/share/nginx/html
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 
-EXPOSE 80
+EXPOSE 8080