fix(backend): 后端日志走查发现 2 个 schema 不一致 bug

- coach_service.py:594 _build_task_groups SQL 查 biz.notes.is_pinned
  但表无该字段 → UndefinedColumn 抛错 + 事务终止 + 级联 _build_notes
  / _build_history_months 全部失败(InFailedSqlTransaction)
  修复:删除 is_pinned 列,pinned 降级 False(置顶功能未落库,
  不影响核心备注展示)。

- customer_service.py:1088 _get_consumption_month_summary SQL 用错
  3 个字段(从 v_dwd_assistant_service_log 复制粘贴未适配
  v_dwd_settlement_head 字段名差异):
    sh.tenant_member_id → sh.member_id
    sh.is_delete = 0 → 删除(view 已过滤已撤销订单)
    sh.settle_time → sh.create_time
  → 高频 UndefinedColumn,小程序 customer-records 月度 rechargeTotal
  恒返回 0,consumption60D 恒返回 null。

走查覆盖(MCP):
- 小程序 customer-records 调 /api/xcx/customers/{id}/consumption-records
  修前: rechargeTotal=0, consumption60D=null
  修后: rechargeTotal=1009.08, consumption60D=7758.24, daysSinceVisit=31
       visitCount=1, consumeTotal=384.02 全部 PASS

发现来源:tmp/20260505_backed_LOG.txt 后端日志 grep
ERROR/Traceback 反复出现 UndefinedColumn。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/backend/app/services/coach_service.py

@@ -589,9 +589,11 @@ def _build_task_groups(
     if task_ids:
         try:
             with conn.cursor() as cur:
+                # 2026-05-05: biz.notes 无 is_pinned 列(SQL 报 UndefinedColumn 触发事务终止 + 级联失败),
+                # 删除该列,pinned 降级 False(置顶功能未落库,不影响核心备注展示)
                 cur.execute(
                     """
-                    SELECT task_id, is_pinned, content, created_at
+                    SELECT task_id, content, created_at
                     FROM biz.notes
                     WHERE task_id = ANY(%s)
                     ORDER BY created_at DESC
@@ -603,9 +605,9 @@ def _build_task_groups(
                     if tid not in task_notes_map:
                         task_notes_map[tid] = []
                     task_notes_map[tid].append({
-                        "pinned": bool(nr[1]),
-                        "text": nr[2] or "",
-                        "date": nr[3].isoformat() if nr[3] else "",
+                        "pinned": False,
+                        "text": nr[1] or "",
+                        "date": nr[2].isoformat() if nr[2] else "",
                     })
         except Exception:
             logger.warning("批量查询任务备注失败", exc_info=True)