fix: Gitea Traefik routing and connection pool optimization

- Remove middleware reference from Gitea Traefik labels (caused routing issues)
- Optimize Gitea connection pool settings (MAX_IDLE_CONNS=30, authentication_timeout=180s)
- Add explicit service reference in Traefik labels
- Fix intermittent 504 timeouts by improving PostgreSQL connection handling

Fixes Gitea unreachability via git.michaelschiemer.de

deployment/stacks/redis/docker-compose.yml

@@ -0,0 +1,37 @@
+services:
+  # Redis Cache & Queue Backend
+  redis-stack:
+    image: redis:7-alpine
+    container_name: redis-stack
+    restart: unless-stopped
+    networks:
+      - app-internal
+    environment:
+      - TZ=Europe/Berlin
+    volumes:
+      - redis-data:/data
+      - ./redis.conf:/usr/local/etc/redis/redis.conf:ro
+      - /etc/timezone:/etc/timezone:ro
+      - /etc/localtime:/etc/localtime:ro
+    command: >
+      redis-server /usr/local/etc/redis/redis.conf
+    healthcheck:
+      test: ["CMD", "redis-cli", "ping"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 10s
+    deploy:
+      resources:
+        limits:
+          memory: 512M
+        reservations:
+          memory: 128M
+
+volumes:
+  redis-data:
+    name: redis-data
+
+networks:
+  app-internal:
+    external: true