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

docker-compose.postgres-override.yml

@@ -1,6 +1,6 @@
-# Shared PostgreSQL Connection Override for Production
+# PostgreSQL Production Connection Override
 #
-# This file provides network configuration for connecting to the PostgreSQL Stack.
+# This file provides network configuration for connecting to the PostgreSQL Production Stack.
 # Used by Production Stack.
 #
 # Usage:
@@ -10,24 +10,27 @@
 #                    -f docker-compose.postgres-override.yml up
 #
 # Prerequisites:
-#   - PostgreSQL Stack must be running (creates app-internal network)
-#   - app-internal network must exist as external network
-#   - PostgreSQL Stack: deployment/stacks/postgresql/docker-compose.yml
+#   - PostgreSQL Production Stack must be running (creates postgres-production-internal network)
+#   - postgres-production-internal network must exist as external network
+#   - PostgreSQL Production Stack: deployment/stacks/postgresql-production/docker-compose.yml
 
 services:
   # Production Stack Services
   # These services will be merged with existing definitions from base.yml + production.yml
   php:
     networks:
-      app-internal: {}  # Add app-internal network for PostgreSQL access (merged with existing networks)
+      postgres-production-internal: {}  # Add postgres-production-internal network for PostgreSQL access (merged with existing networks)
   queue-worker:
     networks:
-      app-internal: {}  # Add app-internal network for PostgreSQL access (merged with existing networks)
+      postgres-production-internal: {}  # Add postgres-production-internal network for PostgreSQL access (merged with existing networks)
   scheduler:
     networks:
-      app-internal: {}  # Add app-internal network for PostgreSQL access
+      postgres-production-internal: {}  # Add postgres-production-internal network for PostgreSQL access
 
 networks:
+  postgres-production-internal:
+    external: true
+    name: postgres-production-internal
   app-internal:
     external: true
     name: app-internal