Add self-contained Gitea Git service with PostgreSQL integration

- Implements complete Gitea Git service following rick-infra self-contained architecture
- Uses PostgreSQL infrastructure role as dependency and manages own database/user
- Native Arch Linux installation via pacman packages
- Automatic database setup (gitea database and user creation)
- SystemD service with security hardening and proper dependency management
- Caddy reverse proxy integration deployed to sites-enabled directory
- SSH server on port 2222 with automatic host key generation
- Production-ready with LFS support, security headers, and HTTPS via Caddy
- Follows simplified configuration approach with essential variables only
- Self-contained pattern: service manages complete setup independently

roles/gitea/handlers/main.yml

@@ -0,0 +1,18 @@
+---
+# Gitea Role Handlers
+
+- name: reload systemd
+  systemd:
+    daemon_reload: yes
+
+- name: restart gitea
+  systemd:
+    name: gitea
+    state: restarted
+  when: gitea_service_state == "started"
+
+- name: reload caddy
+  systemd:
+    name: caddy
+    state: reloaded
+  when: caddy_service_enabled | default(false)