fix(mcp-health): deterministic MCP namespace attachment (Closes #689)

mcp_namespace_health.py

@@ -104,6 +104,8 @@ def classify_namespace_probe(
     profile: str | None = None,
     configured: bool = True,
     probe_source: str | None = None,
+    expected_parity_sha: str | None = None,
+    bound_cohort: dict[str, Any] | None = None,
 ) -> dict[str, Any]:
     """Classify whether a required tool is callable through a live namespace.
 
@@ -135,20 +137,50 @@ def classify_namespace_probe(
         else:
             error_type = "namespace_call_failed"
 
+    # Extract cohort metadata
+    cohort_meta = bound_cohort or probe.get("cohort") or probe.get("bound_cohort") or {}
+    cohort_id = str(
+        cohort_meta.get("cohort_id") or probe.get("cohort_id") or ""
+    ).strip() or None
+    startup_sha = str(
+        cohort_meta.get("startup_sha")
+        or cohort_meta.get("git_head")
+        or probe.get("startup_sha")
+        or probe.get("git_head")
+        or ""
+    ).strip() or None
+    endpoint = str(
+        cohort_meta.get("endpoint") or probe.get("endpoint") or ""
+    ).strip() or None
+    config_fingerprint = str(
+        cohort_meta.get("config_fingerprint") or probe.get("config_fingerprint") or ""
+    ).strip() or None
+
+    expected_sha = (expected_parity_sha or "").strip().lower() or None
+    stale_cohort = False
+    if expected_sha and startup_sha:
+        if startup_sha.lower() != expected_sha:
+            stale_cohort = True
+            error_type = "stale_cohort_refused"
+
     if not configured:
         error_type = "namespace_not_configured"
     elif registered is False:
         error_type = "tool_missing"
     elif not probe_result:
         error_type = "live_probe_missing"
+    elif stale_cohort:
+        error_type = "stale_cohort_refused"
     elif not probe_success and not error_type:
         error_type = "namespace_call_failed"
 
-    callable_live = bool(configured and probe_result and probe_success)
+    callable_live = bool(configured and probe_result and probe_success and not stale_cohort)
     # Probe-path health (spawn or client). IDE-proven only for client path.
     healthy = bool(configured and registered is not False and callable_live)
     ide_namespace_proven = bool(healthy and source == PROBE_SOURCE_CLIENT)
-    process_pid = process.get("pid") if isinstance(process, dict) else None
+    process_pid = process.get("pid") if isinstance(process, dict) else (
+        cohort_meta.get("pid") if isinstance(cohort_meta, dict) else None
+    )
     profile_name = profile or (
         process.get("profile") if isinstance(process, dict) else None
     )
@@ -161,7 +193,13 @@ def classify_namespace_probe(
         reasons.append(
             f"Required tool '{tool}' is not registered in namespace '{ns}'."
         )
-    if error_type == "live_probe_missing":
+    if error_type == "stale_cohort_refused":
+        reasons.append(
+            f"Bound cohort startup SHA '{startup_sha[:12] if startup_sha else 'unknown'}' "
+            f"does not match expected parity SHA '{expected_sha[:12] if expected_sha else 'unknown'}' "
+            "(stale cohort refused)."
+        )
+    elif error_type == "live_probe_missing":
         reasons.append(
             f"No live client invocation proof was supplied for '{ns}.{tool}'."
         )
@@ -248,6 +286,10 @@ def classify_namespace_probe(
             "env": env_summary,
             "config_path": config_path,
             "probe_source": source,
+            "cohort_id": cohort_id,
+            "startup_sha": startup_sha,
+            "endpoint": endpoint,
+            "config_fingerprint": config_fingerprint,
         },
         "blocks_merge_workflow": blocks,
     }