Add Valkey infrastructure role as Redis-compatible cache service

- Implemented complete Valkey infrastructure role following PostgreSQL patterns
- Provides 100% Redis-compatible high-performance data structure store
- Configured for multi-application support with database isolation
- Security-focused: localhost-only binding, password auth, systemd hardening
- Arch Linux compatible: uses native Valkey package with Redis compatibility
- Database allocation strategy: DB 0 reserved, DB 1+ for applications
- Full systemd integration with security overrides and proper service management
- Redis client compatibility maintained for seamless application integration
- Ready for Authentik and future container workloads requiring cache services

roles/valkey/meta/main.yml

@@ -0,0 +1,23 @@
+---
+# Valkey Infrastructure Role - Meta Information
+
+galaxy_info:
+  author: rick-infra
+  description: Valkey (Redis-compatible) infrastructure role for rick-infra project
+  company: Personal Infrastructure
+  license: MIT
+  min_ansible_version: 2.9
+  
+  platforms:
+    - name: ArchLinux
+      versions:
+        - all
+
+  galaxy_tags:
+    - valkey
+    - redis
+    - cache
+    - infrastructure
+    - systemd
+
+# Role provides Valkey infrastructure for other services to consume