build: optimize Postgres container configuration for performance and stability

Updated `dc-infra.yaml` to enable automatic restart (`unless-stopped`), introduce dynamic memory allocations via environment variables, and adjust healthcheck intervals for reduced load. Enhanced `postgresql.conf` with performance tuning comments, schema search path inclusion for Keycloak and app users, and SSL adjustments for internal communication.

config/docker/postgres/postgresql.conf

@@ -1,6 +1,10 @@
 # PostgreSQL Configuration File
 # Optimized for Meldestelle application
 
+# Alle anderen Performance-Werte (shared_buffers etc.) können hier auf
+# den niedrigen Werten bleiben, da sie durch den 'command' oben
+# in der docker-compose dynamisch überschrieben werden.
+
 # Connection Settings
 listen_addresses = '*'
 max_connections = 100
@@ -65,8 +69,9 @@ autovacuum_analyze_scale_factor = 0.025
 autovacuum_vacuum_cost_delay = 20ms
 autovacuum_vacuum_cost_limit = 2000
 
-# Statement Behavior
-search_path = '"$user", public'
+# OPTIMIERUNG: Search Path für Keycloak und App-User
+# Postgres sucht erst im Schema des Users, dann in public, dann in keycloak.
+search_path = '"$user", public, keycloak'
 row_security = on
 
 # Client Connection Defaults
@@ -78,7 +83,7 @@ idle_in_transaction_session_timeout = 600000  # 10 minutes, prevents idle transa
 # Disk
 temp_file_limit = 1GB                   # Limits temp file size
 
-# SSL
+# OPTIMIERUNG: SSL deaktiviert lassen für interne Kommunikation
 ssl = off
 ssl_prefer_server_ciphers = on