fix: orchestrator button + Pi SDK session error

- Move leftSidebarMode from URL state to local useState in unified-shell,
    avoiding force-dynamic router round-trip that made the button appear broken                                           - Replace fileURLToPath(new URL(..., import.meta.url)) with process.cwd()
    in bb-pi-bootstrap.ts — import.meta.url is a webpack:// URL in Next.js,
    causing cross-realm TypeError when passed to Node.js fileURLToPath()

src/tui/tools/bb-worker-status.ts

@@ -0,0 +1,107 @@
+import { Type } from '@sinclair/typebox';
+import type { ToolDefinition } from '@mariozechner/pi-coding-agent';
+import { workerSessionManager } from '../../lib/worker-session-manager';
+
+export function createWorkerStatusTool(projectRoot: string): ToolDefinition {
+  return {
+    name: 'bb_worker_status',
+    label: 'Check Worker Status',
+    description: 'Check the status of a spawned worker agent. Use this to see if a worker is still working, completed successfully, or failed.',
+    parameters: Type.Object({
+      worker_id: Type.String({ description: 'The ID of the worker to check (returned by bb_spawn_worker)' }),
+    }),
+    async execute(_toolCallId, params: any) {
+      try {
+        const { worker_id } = params;
+
+        console.log(`[bb_worker_status] Checking status for worker ${worker_id}`);
+
+        // Validate required param
+        if (!worker_id || typeof worker_id !== 'string') {
+          return {
+            content: [{ type: 'text', text: 'Error: worker_id is required and must be a string.' }],
+            isError: true,
+            details: {},
+          };
+        }
+
+        // Get worker from manager
+        const worker = workerSessionManager.getWorker(worker_id);
+
+        if (!worker) {
+          return {
+            content: [{ type: 'text', text: `Worker ${worker_id} not found. It may not exist or has already been cleaned up.` }],
+            isError: true,
+            details: { workerId: worker_id },
+          };
+        }
+
+        // Build status report
+        const statusEmoji = {
+          spawning: '🔄',
+          working: '🔨',
+          completed: '✅',
+          failed: '❌',
+        };
+
+        let statusMessage = `${statusEmoji[worker.status]} ${worker.status.toUpperCase()}`;
+
+        let details = `Task: ${worker.taskId}
+Created: ${worker.createdAt}
+`;
+
+        if (worker.completedAt) {
+          details += `Completed: ${worker.completedAt}
+`;
+        }
+
+        if (worker.result) {
+          details += `
+Result:
+${worker.result}
+`;
+        }
+
+        if (worker.error) {
+          details += `
+Error: ${worker.error}
+`;
+        }
+
+        // If working, add hint about waiting
+        if (worker.status === 'working') {
+          details += `
+Worker is currently executing. Check again later for completion status.`;
+        }
+
+        // If completed, offer to get more details
+        if (worker.status === 'completed') {
+          details += `
+Use this worker's result in your orchestration decisions. The worker has reported back and is no longer active.`;
+        }
+
+        return {
+          content: [{ type: 'text', text: statusMessage }],
+          details: {
+            workerId: worker.id,
+            taskId: worker.taskId,
+            status: worker.status,
+            createdAt: worker.createdAt,
+            completedAt: worker.completedAt,
+            hasResult: !!worker.result,
+            hasError: !!worker.error,
+          },
+        };
+      } catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        console.error(`[bb_worker_status] Error:`, message);
+
+        return {
+          content: [{ type: 'text', text: `Failed to check worker status: ${message}` }],
+          isError: true,
+          details: { error: message },
+        };
+      }
+    },
+  };
+}