fix: clean up observer sessions on lifecycle end

scripts/hooks/session-end-marker.js

@@ -2,12 +2,50 @@
 'use strict';
 
 /**
- * Session end marker hook - outputs stdin to stdout unchanged.
- * Exports run() for in-process execution (avoids spawnSync issues on Windows).
+ * Session end marker hook - performs lightweight observer cleanup and
+ * outputs stdin to stdout unchanged. Exports run() for in-process execution.
  */
 
+const {
+  resolveProjectContext,
+  removeSessionLease,
+  listSessionLeases,
+  stopObserverForContext,
+  resolveSessionId
+} = require('../lib/observer-sessions');
+
+function log(message) {
+  process.stderr.write(`[SessionEnd] ${message}\n`);
+}
+
 function run(rawInput) {
-  return rawInput || '';
+  const output = rawInput || '';
+  const sessionId = resolveSessionId();
+
+  if (!sessionId) {
+    log('No CLAUDE_SESSION_ID available; skipping observer cleanup');
+    return output;
+  }
+
+  try {
+    const observerContext = resolveProjectContext();
+    removeSessionLease(observerContext, sessionId);
+    const remainingLeases = listSessionLeases(observerContext);
+
+    if (remainingLeases.length === 0) {
+      if (stopObserverForContext(observerContext)) {
+        log(`Stopped observer for project ${observerContext.projectId} after final session lease ended`);
+      } else {
+        log(`No running observer to stop for project ${observerContext.projectId}`);
+      }
+    } else {
+      log(`Retained observer for project ${observerContext.projectId}; ${remainingLeases.length} session lease(s) remain`);
+    }
+  } catch (err) {
+    log(`Observer cleanup skipped: ${err.message}`);
+  }
+
+  return output;
 }
 
 // Legacy CLI execution (when run directly)
@@ -22,7 +60,7 @@ if (require.main === module) {
     }
   });
   process.stdin.on('end', () => {
-    process.stdout.write(raw);
+    process.stdout.write(run(raw));
   });
 }