feat(notify): 站内通知补齐完成、到期逾期与知识事件

backend/app/api/items.py

@@ -205,6 +205,48 @@ async def _apply_update(
     return item
 
 
+async def _notify_status_change(
+    session: AsyncSession,
+    *,
+    ws_id: uuid.UUID,
+    item: Item,
+    previous: str,
+    to_status: str,
+    actor_id: uuid.UUID,
+    actor_name: str,
+) -> None:
+    """状态变化的通知。
+
+    "完成"单独一种 kind：收件人一眼能看出是结项，而不是又一次普通的状态流转；
+    其余状态仍走 `task_status_changed`，正文里写清从什么改成了什么。
+    """
+    if to_status == "done":
+        await notify(
+            session,
+            ws_id=ws_id,
+            user_ids=(item.creator_id, item.assignee_id),
+            kind="task_completed",
+            item_id=item.id,
+            title=f"「{item.title}」已完成",
+            body=f"{actor_name} 把它标记为完成。",
+            actor_id=actor_id,
+        )
+        return
+    await notify(
+        session,
+        ws_id=ws_id,
+        user_ids=(item.creator_id, item.assignee_id),
+        kind="task_status_changed",
+        item_id=item.id,
+        title=f"「{item.title}」变成{TASK_STATUS_CN.get(to_status, to_status)}了",
+        body=(
+            f"{actor_name} 把它从 {TASK_STATUS_CN.get(previous, previous)} "
+            f"改成了 {TASK_STATUS_CN.get(to_status, to_status)}"
+        ),
+        actor_id=actor_id,
+    )
+
+
 # ── 列表 ────────────────────────────────────────────────────────────────
 def _apply_filters(
     stmt: Select,
@@ -581,6 +623,17 @@ async def batch_status(body: BatchStatusIn, ctx: MemberDep, session: SessionDep)
                 }
             )
             continue
+        # 批量改状态以前是"悄悄改完"：被指派人/创建人收不到任何通知，
+        # 和单条改状态的行为不一致。这里补上同一条通知。
+        await _notify_status_change(
+            session,
+            ws_id=ctx.ws_id,
+            item=item,
+            previous=previous,
+            to_status=body.status,
+            actor_id=ctx.user.id,
+            actor_name=ctx.user.nickname or "同事",
+        )
         updated.append({"id": str(item.id), "version": item.version, "unchanged": False})
 
     return ok(
@@ -682,19 +735,14 @@ async def change_status(
         payload={"from": previous, "to": body.status},
     )
     tags = await _tags_of(session, ctx.ws_id, [item.id])
-    await notify(
+    await _notify_status_change(
         session,
         ws_id=ctx.ws_id,
-        user_ids=(item.creator_id, item.assignee_id),
-        kind="task_status_changed",
-        item_id=item.id,
-        title=f"「{item.title}」变成{TASK_STATUS_CN.get(body.status, body.status)}了",
-        body=(
-            f"{ctx.user.nickname or '同事'} 把它从 "
-            f"{TASK_STATUS_CN.get(previous, previous)} 改成了 "
-            f"{TASK_STATUS_CN.get(body.status, body.status)}"
-        ),
+        item=item,
+        previous=previous,
+        to_status=body.status,
         actor_id=ctx.user.id,
+        actor_name=ctx.user.nickname or "同事",
     )
     return ok(_item_out(item, tags.get(item.id)), message="状态已更新")