Bind visualization status to snapshot freshness

tools/milestone1_benchmark.py

@@ -9,6 +9,8 @@ import resource
 import subprocess
 import sys
 import tempfile
+import threading
+import time
 from collections.abc import Callable, Mapping
 from pathlib import Path
 from typing import cast
@@ -24,7 +26,7 @@ from docforge.index import ProjectIndex
 from docforge.mcp_server import DocForgeService
 from docforge.project import Project
 from docforge.rendering import RenderService
-from docforge.viewer_manager import ViewerManagerClient
+from docforge.viewer_manager import ViewerManager, ViewerManagerClient
 
 ROOT = Path(__file__).resolve().parents[1]
 ZERO_WORK_COUNTERS = (
@@ -107,10 +109,6 @@ def _benchmark(root: Path, node_count: int, samples: int) -> dict[str, object]:
     ProjectIndex(project).build()
     RenderService(project).render("manual")
     service = DocForgeService(project, diagnostics=True)
-    service.visualization = ViewerManagerClient(
-        service.index,
-        state_path=root / ".docforge" / "missing-viewer-manager.json",
-    )
     target = synthetic_node_id(node_count - 1)
     operations = {
         "warm_no_change_synchronize": _operation(
@@ -164,13 +162,49 @@ def _benchmark(root: Path, node_count: int, samples: int) -> dict[str, object]:
             samples=samples,
             p95_limit_ms=50,
         ),
-        "visualization_unavailable_status": _operation(
+    }
+    state_path = root / ".docforge" / "benchmark-viewer-manager.json"
+    manager = ViewerManager(state_path, check_interval_seconds=0.02)
+    manager_thread = threading.Thread(target=manager.serve_forever, daemon=True)
+    manager_thread.start()
+    deadline = time.monotonic() + 2
+    while not state_path.exists() and time.monotonic() < deadline:
+        time.sleep(0.01)
+    if not state_path.exists():
+        manager.shutdown()
+        manager_thread.join(timeout=2)
+        raise RuntimeError("Viewer manager did not start")
+    service.visualization = ViewerManagerClient(service.index, state_path=state_path)
+    try:
+        service.visualization.start()
+        operations["visualization_current_status"] = _operation(
             service.visualization_status,
             samples=samples,
             p95_limit_ms=50,
-            expected_status="error",
-        ),
-    }
+        )
+        with service.index.path.open("ab") as stream:
+            stream.write(b"\n")
+        operations["visualization_stale_status"] = _operation(
+            service.visualization_status,
+            samples=samples,
+            p95_limit_ms=50,
+        )
+        service.stop_visualization()
+        operations["visualization_not_running_status"] = _operation(
+            service.visualization_status,
+            samples=samples,
+            p95_limit_ms=50,
+        )
+    finally:
+        manager.shutdown()
+        manager_thread.join(timeout=2)
+    service.visualization = ViewerManagerClient(service.index, state_path=state_path)
+    operations["visualization_unavailable_status"] = _operation(
+        service.visualization_status,
+        samples=samples,
+        p95_limit_ms=50,
+        expected_status="error",
+    )
     return {
         "fixture": {
             "kind": "synthetic_generic",