feat: add Temporal-backed TaskTree service

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

internal/tasktree/workflows.ts

@@ -0,0 +1,11 @@
+import { proxyActivities } from "@temporalio/workflow";
+
+const { recordTaskExecution } = proxyActivities<{ recordTaskExecution(input: { taskId: string }): Promise<{ taskId: string; reportId: string }> }>({
+  startToCloseTimeout: "30 seconds",
+  retry: { maximumAttempts: 3 }
+});
+
+export async function taskExecutionWorkflow(input: { taskId: string }) {
+  const result = await recordTaskExecution(input);
+  return { status: "completed", ...result };
+}