feat(bf-60j): add currentBead field to WorkerInfo

Add currentBead field to WorkerInfo in src/types.ts and maintain it in
src/store.ts: set it from bead.claim.succeeded (event.bead) and clear it
(null) on bead.released. Foundation for the worker-card current-bead
display. Update src/store.test.ts to cover claim->set and release->clear.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/store.test.ts

@@ -231,6 +231,55 @@ describe('InMemoryEventStore', () => {
       expect(worker?.beadsCompleted).toBe(0);
     });
 
+    it('should set currentBead from bead.claim.succeeded event', () => {
+      store.add(createEvent({ worker: 'w-test', msg: 'bead.claim.succeeded', bead: 'bd-abc123' }));
+
+      const worker = store.getWorker('w-test');
+      expect(worker?.currentBead).toBe('bd-abc123');
+    });
+
+    it('should clear currentBead to null on bead.released event', () => {
+      // First set currentBead
+      store.add(createEvent({ worker: 'w-test', msg: 'bead.claim.succeeded', bead: 'bd-abc123' }));
+
+      const workerBefore = store.getWorker('w-test');
+      expect(workerBefore?.currentBead).toBe('bd-abc123');
+
+      // Then release the bead
+      store.add(createEvent({ worker: 'w-test', msg: 'bead.released', bead: 'bd-abc123' }));
+
+      const workerAfter = store.getWorker('w-test');
+      expect(workerAfter?.currentBead).toBeNull();
+    });
+
+    it('should clear currentBead on bead.released regardless of reason', () => {
+      // Set currentBead
+      store.add(createEvent({ worker: 'w-test', msg: 'bead.claim.succeeded', bead: 'bd-xyz' }));
+
+      // Release with non-success reason
+      store.add(createEvent({ worker: 'w-test', msg: 'bead.released', reason: 'release_retry', bead: 'bd-xyz' }));
+
+      const worker = store.getWorker('w-test');
+      expect(worker?.currentBead).toBeNull();
+    });
+
+    it('should update currentBead when worker claims another bead', () => {
+      // Claim first bead
+      store.add(createEvent({ worker: 'w-test', msg: 'bead.claim.succeeded', bead: 'bd-first' }));
+      expect(store.getWorker('w-test')?.currentBead).toBe('bd-first');
+
+      // Claim second bead
+      store.add(createEvent({ worker: 'w-test', msg: 'bead.claim.succeeded', bead: 'bd-second' }));
+      expect(store.getWorker('w-test')?.currentBead).toBe('bd-second');
+    });
+
+    it('should initialize currentBead to null for new workers', () => {
+      store.add(createEvent({ worker: 'w-newbie', msg: 'worker.started' }));
+
+      const worker = store.getWorker('w-newbie');
+      expect(worker?.currentBead).toBeNull();
+    });
+
     it('should track firstSeen timestamp', () => {
       const earlyTs = 1000;
       const lateTs = 5000;

src/store.ts

@@ -622,6 +622,7 @@ export class InMemoryEventStore implements EventStore {
         activeFiles: [],
         hasCollision: false,
         activeBead: event.bead,
+        currentBead: null,
         activeDirectories: [],
         collisionTypes: [],
         eventCount: 1,
@@ -687,14 +688,18 @@ export class InMemoryEventStore implements EventStore {
           worker.activeDirectories = [];
           worker.activeBead = undefined;
         }
-      } else if (needleEvent === 'bead.released' && event['reason'] === 'release_success') {
-        worker.status = 'idle';
-        if (event.bead) {
-          worker.beadsCompleted++;
+      } else if (needleEvent === 'bead.released') {
+        // Clear currentBead on any bead.released event (regardless of reason)
+        worker.currentBead = null;
+        if (event['reason'] === 'release_success') {
+          worker.status = 'idle';
+          if (event.bead) {
+            worker.beadsCompleted++;
+          }
+          worker.activeFiles = [];
+          worker.activeDirectories = [];
+          worker.activeBead = undefined;
         }
-        worker.activeFiles = [];
-        worker.activeDirectories = [];
-        worker.activeBead = undefined;
       } else if (
         needleEvent === 'worker.started' ||
         needleEvent === 'bead.claimed' ||
@@ -705,6 +710,11 @@ export class InMemoryEventStore implements EventStore {
       }
     }
 
+    // Set currentBead from bead.claim.succeeded event
+    if (needleEvent === 'bead.claim.succeeded' && event.bead) {
+      worker.currentBead = event.bead;
+    }
+
     // Update last event
     worker.lastEvent = event;
 

src/types.ts

@@ -551,6 +551,9 @@ export interface WorkerInfo {
   /** Current bead/task being worked on */
   activeBead?: string;
 
+  /** Current bead from bead.claim.succeeded, cleared on bead.released */
+  currentBead: string | null;
+
   /** Directories this worker is active in */
   activeDirectories: string[];