feat(firecracker): enumerate running bottles

bot_bottle/backend/firecracker/enumerate.py

@@ -1,14 +1,32 @@
 """Active-agent enumeration for the Firecracker backend.
 
-The backend is disabled during the companion-container removal (#385) — it can't
+Running bottles are the Firecracker processes whose ``--config-file`` points
-launch bottles, so there are none to enumerate. Real enumeration returns
+at an existing per-bottle run directory. The same authoritative process scan
-with the backend's consolidated relaunch (#354).
+protects cleanup from deleting live VMs; operational scan failures propagate
+as ``EnumerationError`` instead of masquerading as an empty host.
 """
 
 from __future__ import annotations
 
+from ...bottle_state import read_metadata
 from .. import ActiveAgent
+from .cleanup import live_run_dirs
 
 
 def enumerate_active() -> list[ActiveAgent]:
-    return []
+    out: list[ActiveAgent] = []
+    for run_dir in live_run_dirs():
+        slug = run_dir.name
+        metadata = read_metadata(slug)
+        out.append(ActiveAgent(
+            backend_name="firecracker",
+            slug=slug,
+            agent_name=metadata.agent_name if metadata else "?",
+            started_at=metadata.started_at if metadata else "",
+            # Firecracker uses the shared gateway, so there are no
+            # per-bottle gateway service containers to report.
+            services=(),
+            label=metadata.label if metadata else "",
+            color=metadata.color if metadata else "",
+        ))
+    return out

tests/unit/test_firecracker_enumerate.py

@@ -0,0 +1,64 @@
+"""Unit tests for Firecracker active-agent enumeration."""
+
+from __future__ import annotations
+
+import unittest
+from pathlib import Path
+from unittest.mock import patch
+
+from bot_bottle.backend import EnumerationError
+from bot_bottle.backend.firecracker import enumerate as fc_enumerate
+from bot_bottle.bottle_state import BottleMetadata
+
+
+class TestEnumerateActive(unittest.TestCase):
+    def test_maps_live_run_dirs_to_active_agents(self) -> None:
+        metadata = BottleMetadata(
+            identity="dev-a",
+            agent_name="claude",
+            cwd="",
+            copy_cwd=False,
+            started_at="2026-07-26T12:00:00Z",
+            label="review",
+            color="blue",
+        )
+        with (
+            patch.object(
+                fc_enumerate, "live_run_dirs",
+                return_value=(Path("/cache/run/dev-a"),),
+            ),
+            patch.object(fc_enumerate, "read_metadata", return_value=metadata),
+        ):
+            agents = fc_enumerate.enumerate_active()
+        self.assertEqual(1, len(agents))
+        self.assertEqual("firecracker", agents[0].backend_name)
+        self.assertEqual("dev-a", agents[0].slug)
+        self.assertEqual("claude", agents[0].agent_name)
+        self.assertEqual("review", agents[0].label)
+        self.assertEqual((), agents[0].services)
+
+    def test_missing_metadata_uses_safe_defaults(self) -> None:
+        with (
+            patch.object(
+                fc_enumerate, "live_run_dirs",
+                return_value=(Path("/cache/run/dev-a"),),
+            ),
+            patch.object(fc_enumerate, "read_metadata", return_value=None),
+        ):
+            agent = fc_enumerate.enumerate_active()[0]
+        self.assertEqual("?", agent.agent_name)
+        self.assertEqual("", agent.started_at)
+
+    def test_process_scan_failure_propagates(self) -> None:
+        with (
+            patch.object(
+                fc_enumerate, "live_run_dirs",
+                side_effect=EnumerationError("pgrep failed"),
+            ),
+            self.assertRaisesRegex(EnumerationError, "pgrep failed"),
+        ):
+            fc_enumerate.enumerate_active()
+
+
+if __name__ == "__main__":
+    unittest.main()