Implement real-time terminal popup for system rebuild operations

- Add terminal popup UI component with 80% screen coverage and terminal styling
- Extend ZMQ protocol with CommandOutputMessage for streaming output
- Implement real-time output streaming in agent system rebuild handler
- Add keyboard controls (ESC/Q to close, ↑↓ to scroll) for popup interaction
- Fix system panel Build display to show actual NixOS build instead of config hash
- Update service filters in README with wildcard patterns for better matching
- Add periodic progress updates during nixos-rebuild execution
- Integrate command output handling in dashboard main loop

README.md

@@ -152,10 +152,13 @@ interval_seconds = 10
 memory_warning_mb = 1000.0
 memory_critical_mb = 2000.0
 service_name_filters = [
-  "nginx", "postgresql", "redis", "docker", "sshd"
+  "nginx*", "postgresql*", "redis*", "docker*", "sshd*", 
+  "gitea*", "immich*", "haasp*", "mosquitto*", "mysql*", 
+  "unifi*", "vaultwarden*"
 ]
 excluded_services = [
-  "nginx-config-reload", "sshd-keygen"
+  "nginx-config-reload", "sshd-keygen", "systemd-", 
+  "getty@", "user@", "dbus-", "NetworkManager-"
 ]
 
 [notifications]