feat(开发任务): 状态流转接入单条工作流

apps/web/lib/dev-task-workflow.ts

@@ -0,0 +1,49 @@
+import type { DevTask, DevTaskStatus } from './dev-task';
+import { canTransition } from './dev-task';
+
+export interface DevTaskWorkflowResult {
+  ok: boolean;
+  patch?: Partial<DevTask>;
+  message?: string;
+}
+
+export interface DevTaskTransitionOptions {
+  now?: Date;
+  delayReason?: string;
+}
+
+export function normalizeDevTaskOnCreate(task: DevTask): DevTask {
+  return {
+    ...task,
+    status: 'todo',
+    actualStartAt: undefined,
+    actualEndAt: undefined,
+  };
+}
+
+export function applyDevTaskTransition(
+  task: DevTask,
+  to: DevTaskStatus,
+  options: DevTaskTransitionOptions = {},
+): DevTaskWorkflowResult {
+  if (!canTransition(task.status, to)) {
+    return { ok: false, message: `不允许从「${task.status}」流转到「${to}」` };
+  }
+
+  const nowIso = (options.now ?? new Date()).toISOString();
+  const patch: Partial<DevTask> = {
+    status: to,
+    aiDraft: false,
+  };
+
+  if (to === 'in_progress' && !task.actualStartAt) {
+    patch.actualStartAt = nowIso;
+    if (options.delayReason?.trim()) patch.delayReason = options.delayReason.trim();
+  }
+
+  if (to === 'submitted') {
+    patch.actualEndAt = nowIso;
+  }
+
+  return { ok: true, patch };
+}