Implement headless ComfyUI installation and improve backend status handling

- Added a new function to ensure headless installation of ComfyUI when backends are empty, enhancing the setup process for SwarmUI.
- Updated documentation to clarify the installation flow and backend readiness checks, ensuring users understand the requirements for a successful setup.
- Enhanced backend status checks to differentiate between 'empty' and 'idle' states, improving error handling and user feedback during provisioning.
- Adjusted logging messages to provide clearer insights into the installation and backend status processes.

src/gpu_rent/ready.py

@@ -56,10 +56,16 @@ while time.time() < deadline:
         bstat = str(be.get("status") or "unknown").lower()
         if waiting or live or loading:
             print(f"BUSY queue w={waiting} live={live} load={loading}")
-        elif bstat not in ("idle", "disabled", "all_disabled", "empty"):
+        elif bstat == "empty":
+            # No backends registered — Comfy never installed (Install wizard).
+            # Not "Idle": treat as wait, never ready.
+            print("BUSY backend=empty (нужен first-install Comfy)")
+        elif bstat in ("disabled", "all_disabled"):
             print(f"BUSY backend={bstat}")
-        else:
+        elif bstat == "idle":
             print(f"READY backend={bstat}")
+        else:
+            print(f"BUSY backend={bstat}")
         raise SystemExit(0)
     except Exception as exc:
         print(f"WAIT {exc}")
@@ -316,7 +322,13 @@ def verify_gpu_env(
     from gpu_rent.ssh_ops import run_python
 
     # These never "appear later" on a broken image — don't burn the poll budget.
+    # Empty-backend / missing install also won't self-heal without InstallConfirmWS.
     instant_fail_names = {"nvidia-smi", "cuda"}
+    instant_fail_detail_substrings = (
+        "dlbackend пуст",
+        "backend=empty",
+        "Install не прогоняли",
+    )
 
     want_swarm = bool(getattr(cfg, "enable_swarmui", True))
     script = files("gpu_rent.remote").joinpath("stack_env_probe.py").read_text(
@@ -391,6 +403,11 @@ def verify_gpu_env(
             return last
 
         instant = [c for c in hard if c.name in instant_fail_names]
+        if not instant:
+            for c in hard:
+                detail_l = (c.detail or "").lower()
+                if any(s.lower() in detail_l for s in instant_fail_detail_substrings):
+                    instant.append(c)
         if instant:
             for c in last:
                 mark = "ok" if c.ok else "FAIL"
@@ -399,7 +416,8 @@ def verify_gpu_env(
                 failed = [c.name for c in instant]
                 raise CloudError(
                     f"GPU-стек: нет {', '.join(failed)} (fail-fast). "
-                    "Проверь образ Driver / nvidia на VM. "
+                    "Проверь образ Driver / nvidia на VM; для SwarmUI — "
+                    "first-install Comfy (InstallConfirmWS / dlbackend). "
                     "Дальше: gpu-rent status · gpu-rent logs · gpu-rent stop"
                 )
             return last