ai: package llama-server for all three deployments, with idle unload

install_llama_cpp.sh builds llama-server from the SHA-pinned v0.3.0
source tarball (single source of truth: on-device upgrade, Pi image,
Live ISO, and the new docker/llm container all call it; version-marker
makes re-runs no-ops).  start_llama_server.sh refuses to start unless
ai.yaml enables AI and the active model file exists — which also covers
unmounted media.  wrolpi-llm.service is installed but deliberately
never enabled at boot: the Controller starts it on demand (registered
in managed_services; the llm compose service follows the samba
pattern), and the API's perpetual idle-unload worker asks the
Controller to stop it after the configured idle minutes.  llama-server
is localhost-only natively, internal-network-only in docker, and never
proxied by Caddy.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

controller/defaults.py

@@ -78,6 +78,16 @@ DEFAULT_CONFIG = {
             "use_https": True,
             "description": "Kiwix/Zim server",
         },
+        {
+            "name": "wrolpi-llm",
+            "systemd_name": "wrolpi-llm",
+            "port": 11435,
+            "viewable": False,
+            "use_https": False,
+            "description": "AI assistant (llama-server)",
+            # On-demand: started by the Controller when AI is enabled, stopped by the API when idle.
+            "kind": "persistent",
+        },
         # System services
         {
             "name": "caddy",