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/docs/guides/migrate-to-separate-databases.md

@@ -0,0 +1,286 @@
+# Migration Guide: Separate Database Stacks
+
+## Overview
+
+This guide describes how to migrate from a shared PostgreSQL stack to separate database stacks for Production and Staging.
+
+## Current State (Before Migration)
+
+- Single PostgreSQL stack: `deployment/stacks/postgresql/`
+- Both Production and Staging connect to the same database instance
+- Database name: `michaelschiemer` (Production) and `michaelschiemer_staging` (Staging) in same instance
+
+## Target State (After Migration)
+
+- **Production Database**: `deployment/stacks/postgresql-production/`
+  - Container: `postgres-production`
+  - Network: `postgres-production-internal`
+  - Database: `michaelschiemer`
+
+- **Staging Database**: `deployment/stacks/postgresql-staging/`
+  - Container: `postgres-staging`
+  - Network: `postgres-staging-internal`
+  - Database: `michaelschiemer_staging`
+
+## Migration Steps
+
+### Phase 1: Backup Existing Database
+
+**CRITICAL**: Create backups before migration!
+
+```bash
+# On production server
+cd ~/deployment/stacks/postgresql
+
+# Create backup of production database
+docker exec postgres-backup /scripts/backup.sh
+
+# Create backup of staging database (if exists in same instance)
+docker exec postgres psql -U postgres -d michaelschiemer_staging -c "SELECT 1;" && \
+  docker exec postgres-backup /scripts/backup.sh || echo "Staging database not found"
+
+# List backups
+ls -lh backups/
+```
+
+### Phase 2: Deploy New Database Stacks
+
+#### 2.1 Deploy PostgreSQL Production Stack
+
+```bash
+# On production server
+cd ~/deployment/stacks/postgresql-production
+
+# Create .env file
+cat > .env <<EOF
+POSTGRES_DB=michaelschiemer
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=<same-as-production-password>
+BACKUP_RETENTION_DAYS=7
+BACKUP_SCHEDULE=0 2 * * *
+EOF
+
+# Start PostgreSQL Production
+docker compose up -d
+
+# Verify
+docker compose ps
+docker exec postgres-production pg_isready -U postgres -d michaelschiemer
+```
+
+#### 2.2 Deploy PostgreSQL Staging Stack
+
+```bash
+# On production server
+cd ~/deployment/stacks/postgresql-staging
+
+# Create .env file
+cat > .env <<EOF
+POSTGRES_DB=michaelschiemer_staging
+POSTGRES_USER=postgres
+POSTGRES_PASSWORD=<staging-password-can-differ>
+BACKUP_RETENTION_DAYS=3
+BACKUP_SCHEDULE=0 3 * * *
+EOF
+
+# Start PostgreSQL Staging
+docker compose up -d
+
+# Verify
+docker compose ps
+docker exec postgres-staging pg_isready -U postgres -d michaelschiemer_staging
+```
+
+### Phase 3: Restore Data to New Stacks
+
+#### 3.1 Restore Production Database
+
+```bash
+# Find latest production backup
+LATEST_PROD_BACKUP=$(ls -t ~/deployment/stacks/postgresql/backups/postgres_michaelschiemer_*.sql.gz | head -1)
+
+# Copy backup to new stack
+cp "$LATEST_PROD_BACKUP" ~/deployment/stacks/postgresql-production/backups/
+
+# Restore to new production database
+cd ~/deployment/stacks/postgresql-production
+docker exec -it postgres-production-backup /scripts/restore.sh "/backups/$(basename $LATEST_PROD_BACKUP)"
+```
+
+#### 3.2 Restore Staging Database (if exists)
+
+```bash
+# Find latest staging backup (if exists)
+LATEST_STAGING_BACKUP=$(ls -t ~/deployment/stacks/postgresql/backups/postgres_michaelschiemer_staging_*.sql.gz 2>/dev/null | head -1)
+
+if [ -n "$LATEST_STAGING_BACKUP" ]; then
+  # Copy backup to new stack
+  cp "$LATEST_STAGING_BACKUP" ~/deployment/stacks/postgresql-staging/backups/
+  
+  # Restore to new staging database
+  cd ~/deployment/stacks/postgresql-staging
+  docker exec -it postgres-staging-backup /scripts/restore.sh "/backups/$(basename $LATEST_STAGING_BACKUP)"
+else
+  echo "No staging backup found - creating empty staging database"
+fi
+```
+
+### Phase 4: Update Application Stacks
+
+#### 4.1 Update Production Application Stack
+
+The Production Application Stack should already be configured to use `postgres-production` via:
+- Environment variable: `DB_HOST=postgres-production`
+- Network: Connected to `postgres-production-internal`
+
+**Verify connection**:
+```bash
+cd ~/deployment/stacks/production
+docker compose -f docker-compose.base.yml -f docker-compose.production.yml exec app \
+  php -r "echo 'DB Connection: '; \$pdo = new PDO('pgsql:host=postgres-production;dbname=michaelschiemer', 'postgres', getenv('DB_PASSWORD')); echo 'OK\n';"
+```
+
+#### 4.2 Update Staging Application Stack
+
+The Staging Application Stack should already be configured to use `postgres-staging` via:
+- Environment variable: `DB_HOST=postgres-staging`
+- Network: Connected to `postgres-staging-internal`
+
+**Verify connection**:
+```bash
+cd ~/deployment/stacks/staging
+docker compose -f docker-compose.base.yml -f docker-compose.staging.yml exec staging-app \
+  php -r "echo 'DB Connection: '; \$pdo = new PDO('pgsql:host=postgres-staging;dbname=michaelschiemer_staging', 'postgres', getenv('DB_PASSWORD')); echo 'OK\n';"
+```
+
+### Phase 5: Verify Migration
+
+#### 5.1 Production Verification
+
+```bash
+# Check production database
+docker exec postgres-production psql -U postgres -d michaelschiemer -c "\dt"
+
+# Check production application
+curl -k https://michaelschiemer.de/health
+
+# Check production logs
+cd ~/deployment/stacks/production
+docker compose logs app | tail -20
+```
+
+#### 5.2 Staging Verification
+
+```bash
+# Check staging database
+docker exec postgres-staging psql -U postgres -d michaelschiemer_staging -c "\dt"
+
+# Check staging application
+curl -k https://staging.michaelschiemer.de/health
+
+# Check staging logs
+cd ~/deployment/stacks/staging
+docker compose logs staging-app | tail -20
+```
+
+### Phase 6: Cleanup (Optional)
+
+**WARNING**: Only remove old stack after successful migration and verification!
+
+```bash
+# Stop old PostgreSQL stack
+cd ~/deployment/stacks/postgresql
+docker compose down
+
+# Keep backups for safety - do NOT delete yet
+# Consider keeping for at least 30 days
+
+# Remove old stack (only after 30+ days of successful operation)
+# rm -rf ~/deployment/stacks/postgresql
+```
+
+## Rollback Plan
+
+If migration fails:
+
+### Rollback to Shared Database
+
+```bash
+# 1. Stop new database stacks
+cd ~/deployment/stacks/postgresql-production
+docker compose down
+
+cd ~/deployment/stacks/postgresql-staging
+docker compose down
+
+# 2. Restart old shared stack
+cd ~/deployment/stacks/postgresql
+docker compose up -d
+
+# 3. Update application stacks to use old database
+# Revert DB_HOST changes in docker-compose files
+# Restart application stacks
+```
+
+## Network Configuration
+
+### Production Application Stack
+
+Must be connected to:
+- `traefik-public` (for external access)
+- `postgres-production-internal` (for database access)
+- `app-internal` (for Redis, if shared)
+
+### Staging Application Stack
+
+Must be connected to:
+- `traefik-public` (for external access)
+- `postgres-staging-internal` (for database access)
+- `staging-internal` (for staging services)
+
+## Backup Strategy
+
+### Production Backups
+
+- **Location**: `~/deployment/stacks/postgresql-production/backups/`
+- **Retention**: 7 days
+- **Schedule**: Daily at 2:00 AM
+
+### Staging Backups
+
+- **Location**: `~/deployment/stacks/postgresql-staging/backups/`
+- **Retention**: 3 days
+- **Schedule**: Daily at 3:00 AM
+
+## Troubleshooting
+
+### Database Connection Refused
+
+```bash
+# Check if database container is running
+docker ps | grep postgres-production
+docker ps | grep postgres-staging
+
+# Check network connectivity
+docker network inspect postgres-production-internal
+docker network inspect postgres-staging-internal
+
+# Test connection from application container
+docker exec <app-container> nc -zv postgres-production 5432
+docker exec <app-container> nc -zv postgres-staging 5432
+```
+
+### Migration Data Loss
+
+If data is missing after migration:
+
+1. **Stop application** to prevent further writes
+2. **Restore from backup** (see Phase 3)
+3. **Verify data** before restarting application
+
+## Additional Resources
+
+- **PostgreSQL Production Stack**: `deployment/stacks/postgresql-production/README.md`
+- **PostgreSQL Staging Stack**: `deployment/stacks/postgresql-staging/README.md`
+- **Backup Playbook**: `deployment/ansible/playbooks/backup.yml`
+