feat: comprehensive security, performance, UX and deployment audit

Security:
- CORS restricted to explicit methods/headers, configurable via CORS_ORIGINS env
- Auth added to /reports/{rid}/html and /compliance-report endpoints
- Ownership check on report downloads
- Rate limiting on login (10 attempts/5min per IP with threading.Lock)
- Non-root container user (agent via gosu entrypoint)
- Nginx security headers (X-Frame-Options, X-Content-Type-Options, X-XSS-Protection, Referrer-Policy, Permissions-Policy)
- .gitignore and .dockerignore for secret leak prevention
- .env.example with documentation

Performance:
- 16 SQLite indexes on foreign keys and frequently queried columns
- Pagination on chat messages (100), reports (50), audit log (100)
- subprocess.run wrapped in run_in_executor (3 async handlers)
- asyncio.wait_for timeouts on GenAI calls (300s) and Chromium PDF (120s)
- Thread pool reduced to 10 workers
- Code splitting with React.lazy (bundle: 1.3MB -> ~550KB initial)
- React.memo on TreeItem (recursive compartment tree)

Error handling:
- 13 bare except clauses replaced with logged Exception handlers
- Graceful shutdown handler (terminates subprocesses + executor)
- File upload validation (50MB max, extension whitelist per endpoint)
- Health check expanded (version, uptime, db_ok)
- Cache-Control on /api/genai/models (1h)
- Auto-cleanup audit_log > 30 days

Dead code removed:
- DownloadsPage.tsx, StubPage.tsx, MfaPage.tsx (moved to UsersPage)
- Legacy frontend/ directory
- 19 unused i18n keys, dist/ removed from git tracking

UX & i18n:
- 8 alert() calls replaced with styled error states (TerraformPage)
- 50+ hardcoded Portuguese strings localized to i18n (pt/en) across 11 files
- aria-label on all icon-only buttons (Chat, Explorer, Sidebar)
- focus-visible CSS for keyboard navigation
- Responsive grid fix (360px -> 280px for mobile)
- aria-hidden on decorative SVGs

Deployment:
- Docker resource limits (backend 4G, frontend 512M)
- Log rotation (json-file, 10MB x 3)
- Terraform version parameterized via ARG

docker-compose.yml

@@ -9,6 +9,7 @@ services:
       - APP_SECRET=${APP_SECRET:-change-me-in-production-use-a-long-random-string}
       - JWT_EXPIRY_HOURS=${JWT_EXPIRY_HOURS:-12}
       - DATA_DIR=/data
+      - CORS_ORIGINS=${CORS_ORIGINS:-}
       - OCI_CLI_SUPPRESS_FILE_PERMISSIONS_WARNING=True
     volumes:
       - agent-data:/data
@@ -19,6 +20,15 @@ services:
       interval: 30s
       timeout: 10s
       retries: 3
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "10m"
+        max-file: "3"
+    deploy:
+      resources:
+        limits:
+          memory: 4G
 
   frontend:
     image: nginx:alpine
@@ -27,13 +37,21 @@ services:
     volumes:
       - ./frontend-react/dist:/usr/share/nginx/html/app:ro
       - ./nginx/default.conf:/etc/nginx/conf.d/default.conf:ro
-    # Note: nginx root points to /usr/share/nginx/html/app (React dist)
     ports:
       - "${PORT:-8080}:80"
     depends_on:
       - backend
     networks:
       - agent-net
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "5m"
+        max-file: "3"
+    deploy:
+      resources:
+        limits:
+          memory: 512M
 
 volumes:
   agent-data: