feat(wechat): add Intent Transaction Layer with unified task schema

Introduce Draft → Confirm → Commit flow for WeChat schedule intents behind
feature flags, plus h5_tasks dual-write/read aggregation and rollout scripts
so reminders and automations get explicit user confirmation before persisting.

Co-authored-by: Cursor <cursoragent@cursor.com>

intent-draft-service.test.mjs

@@ -0,0 +1,121 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createIntentDraftService } from './intent-draft-service.mjs';
+
+function createMemoryPool() {
+  const rows = new Map();
+  return {
+    async query(sql, params = []) {
+      if (sql.includes('UPDATE h5_intent_drafts') && sql.includes("status = 'expired'")) {
+        return [{ affectedRows: 0 }];
+      }
+      if (sql.includes('UPDATE h5_intent_drafts') && sql.includes("status = 'cancelled'") && sql.includes("status = 'draft'")) {
+        for (const row of rows.values()) {
+          if (row.user_id === params[1] && row.status === 'draft') {
+            row.status = 'cancelled';
+            row.updated_at = params[0];
+          }
+        }
+        return [{ affectedRows: 1 }];
+      }
+      if (sql.includes('INSERT INTO h5_intent_drafts')) {
+        const id = params[0];
+        rows.set(id, {
+          id,
+          user_id: params[1],
+          layer: params[2],
+          draft_type: params[3],
+          action_level: params[4],
+          title: params[5],
+          payload_json: params[6],
+          card_text: params[7],
+          status: 'draft',
+          source_channel: params[9],
+          source_message_id: params[10],
+          source_text: params[11],
+          committed_ref_json: null,
+          event_log_json: params[12],
+          expires_at: params[13],
+          created_at: params[14],
+          updated_at: params[15],
+        });
+        return [{ affectedRows: 1 }];
+      }
+      if (sql.includes('SELECT * FROM h5_intent_drafts WHERE id = ? AND user_id = ?')) {
+        const row = rows.get(params[0]);
+        return [[row && row.user_id === params[1] ? row : undefined].filter(Boolean)];
+      }
+      if (sql.includes('SELECT * FROM h5_intent_drafts') && sql.includes('user_id = ?') && sql.includes("status = 'draft'")) {
+        const userId = params[0];
+        const draft = [...rows.values()]
+          .filter((row) => row.user_id === userId && row.status === 'draft')
+          .sort((a, b) => b.created_at - a.created_at)[0];
+        return [[draft ?? undefined].filter(Boolean)];
+      }
+      if (sql.includes('SELECT * FROM h5_intent_drafts WHERE id = ?')) {
+        const row = rows.get(params[0]);
+        return [[row].filter(Boolean)];
+      }
+      if (sql.includes("SET status = 'cancelled'") && sql.includes('WHERE id = ?')) {
+        const row = rows.get(params[2]);
+        if (row) {
+          row.status = 'cancelled';
+          row.event_log_json = params[0];
+          row.updated_at = params[1];
+        }
+        return [{ affectedRows: 1 }];
+      }
+      if (sql.includes("SET status = 'committed'")) {
+        const row = rows.get(params[3]);
+        if (row) {
+          row.status = 'committed';
+          row.committed_ref_json = params[0];
+          row.event_log_json = params[1];
+          row.updated_at = params[2];
+        }
+        return [{ affectedRows: 1 }];
+      }
+      throw new Error(`Unexpected SQL: ${sql}`);
+    },
+  };
+}
+
+test('createDraft replaces previous pending draft for same user', async () => {
+  const pool = createMemoryPool();
+  const service = createIntentDraftService(pool, { clock: { now: () => 1000 }, ttlMs: 60000 });
+  const first = await service.createDraft({
+    userId: 'user-1',
+    layer: 'L1',
+    draftType: 'timed_reminder',
+    title: '第一次',
+    payload: { title: '第一次' },
+    cardText: 'card-1',
+  });
+  const second = await service.createDraft({
+    userId: 'user-1',
+    layer: 'L1',
+    draftType: 'timed_reminder',
+    title: '第二次',
+    payload: { title: '第二次' },
+    cardText: 'card-2',
+  });
+  const pending = await service.getPendingDraft('user-1');
+  assert.notEqual(first.id, second.id);
+  assert.equal(pending.title, '第二次');
+});
+
+test('markDraftCommitted stores committed ref', async () => {
+  const pool = createMemoryPool();
+  const service = createIntentDraftService(pool, { clock: { now: () => 2000 }, ttlMs: 60000 });
+  const draft = await service.createDraft({
+    userId: 'user-1',
+    layer: 'L1',
+    draftType: 'create_todo',
+    title: '跟进合同',
+    payload: { title: '跟进合同' },
+    cardText: 'card',
+  });
+  const committed = await service.markDraftCommitted(draft.id, 'user-1', { kind: 'create_todo', item: { id: 'item-1' } });
+  assert.equal(committed.status, 'committed');
+  assert.deepEqual(committed.committedRef, { kind: 'create_todo', item: { id: 'item-1' } });
+});