- Implement list_firewall_rules with full rule configuration parsing
- Implement add_rule, delete_rule, update_rule
- Implement enable_firewall and disable_firewall
- Implement get_firewall_status with full status details
- Implement get_firewall_zone and list_firewall_zones
- All operations use proper error handling with Option safety
- Add 2 unit tests for firewall rule and status serialization
- Add proxmox module with client, cluster, and resource management
- Implement VM management stubs with full API documentation
- Add database migrations for proxmox_clusters and proxmox_resources tables
- Implement IPC commands for cluster CRUD operations
- Add Proxmox state management to AppState
- Create 22 unit tests for Proxmox modules (all passing)
- Update lib.rs, state.rs, and integrations.rs for Proxmox integration
