Refactor LLM runtime handling and enhance CLI documentation

- Updated `resolve_llm_runtime` to prioritize live configuration over legacy notes, ensuring accurate runtime resolution.
- Enhanced `tunnel_forwards` to prefer current configuration for LLM runtime, improving tunnel setup logic.
- Improved idle-killer logic to handle stale markers and provide clearer warnings in the status output.
- Updated CLI documentation in `cli.md` to reflect changes in command behavior and runtime handling.
- Enhanced tests to validate new runtime resolution logic and ensure proper handling of configuration states.

src/gpu_rent/tunnel.py

@@ -72,16 +72,12 @@ def decide_watch(status: str | None, tunnel_alive: bool) -> WatchDecision:
 
 
 def tunnel_forwards(cfg: Config) -> list[tuple[int, int]]:
-    """List of (local_port, remote_port). SwarmUI always; LLM if configured."""
+    """List of (local_port, remote_port). SwarmUI always; LLM if configured.
+
+    Prefer live config (`LLM_RUNTIME`) over stale state.notes.
+    """
     pairs = [(cfg.swarmui_local_port, 7801)]
     runtime = normalize_runtime(cfg.llm_runtime)
-    state = load_state()
-    noted = (state.notes or {}).get("llm_runtime")
-    if noted:
-        try:
-            runtime = normalize_runtime(str(noted))
-        except ValueError:
-            pass
     if runtime == "ollama":
         pairs.append((cfg.ollama_local_port, 11434))
     elif runtime == "llamacpp":