feat(agent): L1 记忆注入——重试任务带上次失败原因喂回 prompt

- store.lastRunErrorOf(taskId)：取最近一次失败 run 的 error（任意 kind）
- orchestrator.claimOne：写 job.json 时填充 task.lastRunError 下发 worker
- runner 三处 prompt（executor/planner/conflict）注入「## 上次失败原因」段（截断 2000 字符）

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/daemon/orchestrator.ts

@@ -174,9 +174,12 @@ export function createOrchestrator(store: Store, log: OrchestratorLogger, deps:
       const run = store.startRun(task.id, dbKind, { worktree: isPlanner ? project.repoPath : dir, branch });
       runId = run.id;
 
+      // L1 记忆注入：重试任务带上「上次失败原因」，worker 端拼进 prompt（见 runner.buildPrompt*）
+      const lastRunError = store.lastRunErrorOf(task.id);
+
       d.writeJobSpec({
         runId: run.id,
-        task: { ...task, status: isPlanner ? task.status : 'executing' },
+        task: { ...task, status: isPlanner ? task.status : 'executing', lastRunError },
         project, worktreeDir: dir, branch, runKind,
       });