Update documentation and CLI behavior for GPU management

- Clarified the behavior of `Ctrl+C` and `Ctrl+D` in the README and other documentation, specifying that `Ctrl+C` only stops the tunnel while keeping the GPU active, and `Ctrl+D` stops the GPU while preserving disk data.
- Enhanced the CLI documentation to reflect these changes, ensuring users understand the implications of these commands during GPU operations.
- Improved the handling of data bindings and remounting logic in the codebase to prevent issues with empty model tabs in the UI.
- Added tests to validate the new command behaviors and ensure proper documentation alignment.

tests/test_verify_stack.py

@@ -181,3 +181,11 @@ def test_verify_gpu_env_llm_only_skips_torch_requirement(monkeypatch):
     logs: list[str] = []
     out = verify_gpu_env(C(), "1.2.3.4", logs.append, timeout=5.0)
     assert all(c.ok for c in out)
+
+
+def test_stack_probe_requires_ollama_models():
+    from gpu_rent.ready import _REMOTE_STACK_PROBE
+
+    assert "/api/tags" in _REMOTE_STACK_PROBE
+    assert "0 models" in _REMOTE_STACK_PROBE
+    assert 'payload.get("models")' in _REMOTE_STACK_PROBE