Enhance SwarmUI integration and GPU environment verification

- Updated CLI documentation to reflect the new handling of `CIVITAI_API_TOKEN`, which is now automatically passed to SwarmUI user settings during startup.
- Improved the `render_access_panel` function to include additional warnings for idle-killer failures and stack errors, enhancing user feedback.
- Introduced a new function `seed_swarmui_api_keys` to manage API key injection into SwarmUI, ensuring seamless integration with the Model Downloader.
- Enhanced GPU environment verification logic to include fail-fast checks for critical components like CUDA, improving error handling and user notifications.
- Updated tests to validate the new API key handling and access panel behavior, ensuring robustness in the integration process.

src/gpu_rent/provision.py

@@ -228,6 +228,50 @@ def _download_url(host: str, version_id: int, file_info: dict) -> str:
     return f"https://{host}/api/download/models/{version_id}"
 
 
+def seed_swarmui_api_keys(cfg: Config, host: str, log: Log) -> None:
+    """Write CIVITAI_API_TOKEN (and HF if set) into SwarmUI user keys via SetAPIKey.
+
+    Swarm stores them in Users.ldb GenericData — needed for Model Downloader in the UI.
+    Call after SwarmUI HTTP is up (after wait_backend / verify).
+    """
+    import os
+
+    keys: dict[str, str] = {}
+    if cfg.civitai_api_token:
+        keys["civitai_api"] = cfg.civitai_api_token
+    hf = (
+        os.environ.get("HF_TOKEN")
+        or os.environ.get("HUGGING_FACE_HUB_TOKEN")
+        or ""
+    ).strip()
+    if hf:
+        keys["huggingface_api"] = hf
+    if not keys:
+        log("SwarmUI API keys: нет CIVITAI_API_TOKEN / HF_TOKEN — skip")
+        return
+    put_text(
+        cfg,
+        host,
+        "/tmp/gpu-rent-swarm-api-keys.json",
+        json.dumps(keys) + "\n",
+        mode=0o600,
+    )
+    names = ", ".join(keys)
+    log(f"SwarmUI: прокидываю API keys ({names})")
+    try:
+        run_python(
+            cfg,
+            host,
+            _pkg_text("swarmui_set_api_keys.py"),
+            remote_path="/tmp/gpu-rent-swarmui_set_api_keys.py",
+            timeout=180,
+            log=log,
+        )
+    except CloudError as exc:
+        log(f"⚠ SwarmUI API keys: {exc}")
+        run_ssh(cfg, host, "rm -f /tmp/gpu-rent-swarm-api-keys.json", check=False)
+
+
 def seed_civitai(cfg: Config, host: str, log: Log) -> None:
     entries = parse_models(cfg.models_manifest)
     if not cfg.civitai_api_token: