refactor(backend): add list_running() to VmBackend seam (W1)

operations.vms.list_live_vms needs a backend-agnostic running-VM list for the web dashboard; is_running now shares the single vmrun-list parse.

src/ci_orchestrator/backends/protocol.py

@@ -79,3 +79,14 @@ class VmBackend(Protocol):
         getGuestIPAddress``) for this check — see ``AGENTS.md`` error #10.
         """
         ...
+
+    def list_running(self) -> list[VmHandle]:
+        """Return a handle for every VM the backend reports as running.
+
+        Powers the read-only inventory in the web UI and orphan
+        reconciliation. Like :meth:`is_running`, implementations MUST NOT
+        rely on guest tools (see ``AGENTS.md`` error #10) — a plain
+        power-state listing is enough. Handle ``identifier`` is the
+        backend-native reference (a VMX path on Workstation).
+        """
+        ...

src/ci_orchestrator/backends/workstation.py

@@ -140,22 +140,37 @@ class WorkstationVmrunBackend:
             lines = lines[1:]
         return lines
 
+    def list_running(self) -> list[VmHandle]:
+        """``vmrun list`` → one :class:`VmHandle` per running VMX path.
+
+        Skips the ``Total running VMs: N`` header and any ``Error:`` lines
+        (``AGENTS.md`` error #9). Does NOT call ``getGuestIPAddress`` (error
+        #10). The handle ``name`` is the VMX file stem. Returns ``[]`` when
+        ``vmrun list`` fails.
+        """
+        result = self._run("list", check=False)
+        if result.returncode != 0:
+            return []
+        handles: list[VmHandle] = []
+        for raw in (result.stdout or "").splitlines():
+            line = raw.strip()
+            low = line.lower()
+            if not line or low.startswith("total running") or low.startswith("error:"):
+                continue
+            handles.append(VmHandle(identifier=line, name=Path(line).stem))
+        return handles
+
     def is_running(self, handle: VmHandle) -> bool:
         """``vmrun list`` lookup — does NOT call ``getGuestIPAddress``.
 
         See ``AGENTS.md`` error #10: ``getGuestIPAddress`` blocks for 30-60s
-        without VMware Tools. ``vmrun list`` returns immediately.
+        without VMware Tools. ``vmrun list`` returns immediately. Shares the
+        single parse in :meth:`list_running`.
         """
-        result = self._run("list", check=False)
-        if result.returncode != 0:
-            return False
         target = Path(handle.identifier).resolve()
-        for line in (result.stdout or "").splitlines():
-            line = line.strip()
-            if not line or line.lower().startswith("total running"):
-                continue
+        for running in self.list_running():
             try:
-                if Path(line).resolve() == target:
+                if Path(running.identifier).resolve() == target:
                     return True
             except OSError:
                 continue

tests/python/test_backends_protocol.py

@@ -52,3 +52,4 @@ def test_protocol_stubs_are_callable() -> None:
     assert b.get_ip(h) is None                                      # line 69
     assert b.list_snapshots(h) is None                              # line 73
     assert b.is_running(h) is None                                  # line 81
+    assert b.list_running() is None                                 # list_running stub

tests/python/test_workstation_backend.py

@@ -164,6 +164,36 @@ def test_is_running_returns_false_when_absent(
     assert backend.is_running(VmHandle(str(vmx))) is False
 
 
+# ── list_running ─────────────────────────────────────────────────────────────
+
+def test_list_running_parses_paths_and_skips_noise(
+    monkeypatch: pytest.MonkeyPatch, fake_vmrun: str
+) -> None:
+    """Header and ``Error:`` lines are dropped; each VMX becomes a handle."""
+    stdout = (
+        "Total running VMs: 2\n"
+        "/var/lib/ci/build-vms/Clone_a/Clone_a.vmx\n"
+        "Error: The VMware Tools are not running\n"
+        "/var/lib/ci/build-vms/Clone_b/Clone_b.vmx\n"
+    )
+    monkeypatch.setattr(subprocess, "run", lambda *a, **kw: _make_completed(0, stdout=stdout))
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    handles = backend.list_running()
+    assert [h.identifier for h in handles] == [
+        "/var/lib/ci/build-vms/Clone_a/Clone_a.vmx",
+        "/var/lib/ci/build-vms/Clone_b/Clone_b.vmx",
+    ]
+    assert [h.name for h in handles] == ["Clone_a", "Clone_b"]
+
+
+def test_list_running_returns_empty_on_failure(
+    monkeypatch: pytest.MonkeyPatch, fake_vmrun: str
+) -> None:
+    monkeypatch.setattr(subprocess, "run", lambda *a, **kw: _make_completed(1, stderr="boom"))
+    backend = WorkstationVmrunBackend(vmrun_path=fake_vmrun)
+    assert backend.list_running() == []
+
+
 # ── _resolve_vmrun(explicit=None) paths ───────────────────────────────────────
 
 def test_resolve_vmrun_uses_which(monkeypatch: pytest.MonkeyPatch, fake_vmrun: str) -> None: