Add simplified PostgreSQL infrastructure role for database services

- Provides PostgreSQL server as shared database infrastructure
- Follows KISS principle with only essential configuration (11 variables vs 45 originally)
- Implements maximum security with Unix socket-only superuser access
- Uses scram-sha-256 authentication for application users
- Includes SystemD security hardening
- Applications manage their own databases/users via this infrastructure
- Production-ready with data checksums and localhost-only access

roles/postgresql/meta/main.yml

@@ -0,0 +1,25 @@
+---
+galaxy_info:
+  author: Rick's Infrastructure Team
+  description: PostgreSQL database server infrastructure for rick-infra
+  company: Personal Infrastructure
+  
+  license: MIT
+  
+  min_ansible_version: "2.9"
+  
+  platforms:
+    - name: ArchLinux
+      versions:
+        - all
+  
+  galaxy_tags:
+    - database
+    - postgresql
+    - infrastructure
+    - archlinux
+
+dependencies: []
+
+# Role provides PostgreSQL infrastructure
+# Applications should declare this as a dependency and manage their own databases/users