feat(notification): 通知标题和正文支持多语言

- 通知静态配置支持 title/body i18n
- 前端通知列表和详情页展示本地化内容
- 新增数据库迁移脚本
- 更新通知协议文档

backend/tests/unit/test_notification_service.py

@@ -5,7 +5,12 @@ from uuid import UUID, uuid4
 
 import pytest
 
-from v1.notifications.service import NotificationService, _parse_payload
+from v1.notifications.service import (
+    NotificationService,
+    _parse_payload,
+    resolve_i18n_text,
+    normalize_locale,
+)
 from v1.notifications.schemas import (
     NotificationPayloadNone,
     NotificationPayloadRoute,
@@ -39,8 +44,8 @@ class _FakeNotification:
         *,
         id: UUID,
         type: str = "system",
-        title: str = "Test",
-        body: str = "Test body",
+        title: dict[str, str] | None = None,
+        body: dict[str, str] | None = None,
         payload: dict | None = None,
         status: str = "published",
         deleted_at: datetime | None = None,
@@ -48,8 +53,8 @@ class _FakeNotification:
     ):
         self.id = id
         self.type = type
-        self.title = title
-        self.body = body
+        self.title = title or {"zh": "Test"}
+        self.body = body or {"zh": "Test body"}
         self.payload = payload or {"action": "none"}
         self.status = status
         self.deleted_at = deleted_at
@@ -154,8 +159,8 @@ def _make_notification(
     notification_id: UUID | None = None,
     is_read: bool = False,
     read_at: datetime | None = None,
-    title: str = "Test",
-    body: str = "Test body",
+    title: dict[str, str] | None = None,
+    body: dict[str, str] | None = None,
     payload: dict | None = None,
     status: str = "published",
     deleted_at: datetime | None = None,
@@ -185,8 +190,12 @@ class TestListNotifications:
     async def test_returns_only_user_a_notifications(
         self, service: NotificationService, fake_repo: _FakeNotificationRepository
     ):
-        un_a, n_a = _make_notification(user_id=USER_A, title="A1")
-        un_b, n_b = _make_notification(user_id=USER_B, title="B1")
+        un_a, n_a = _make_notification(
+            user_id=USER_A, title={"zh": "A1"}, body={"zh": "A1 body"},
+        )
+        un_b, n_b = _make_notification(
+            user_id=USER_B, title={"zh": "B1"}, body={"zh": "B1 body"},
+        )
         fake_repo.add_item(un_a, n_a)
         fake_repo.add_item(un_b, n_b)
 
@@ -219,7 +228,9 @@ class TestListNotifications:
         self, service: NotificationService, fake_repo: _FakeNotificationRepository
     ):
         for i in range(3):
-            un, n = _make_notification(user_id=USER_A, title=f"N{i}")
+            un, n = _make_notification(
+                user_id=USER_A, title={"zh": f"N{i}"}, body={"zh": f"N{i} body"},
+            )
             fake_repo.add_item(un, n)
 
         result = await service.list_notifications(user_id=USER_A, limit=2)
@@ -383,3 +394,75 @@ class TestParsePayload:
         assert payload.route == "/settings"
         assert payload.entity_id is None
         assert payload.tab is None
+
+
+class TestResolveI18nText:
+    def test_exact_locale_match(self):
+        text = resolve_i18n_text({"zh": "你好", "en": "Hello"}, "en")
+        assert text == "Hello"
+
+    def test_falls_back_to_default(self):
+        text = resolve_i18n_text({"zh": "你好", "en": "Hello"}, "zh_Hant")
+        assert text == "你好"
+
+    def test_returns_empty_when_default_missing(self):
+        text = resolve_i18n_text({"en": "Hello"}, "zh_Hant")
+        assert text == ""
+
+    def test_empty_dict(self):
+        text = resolve_i18n_text({}, "en")
+        assert text == ""
+
+
+class TestNormalizeLocale:
+    def test_known_locale_passthrough(self):
+        assert normalize_locale("zh") == "zh"
+        assert normalize_locale("zh_Hant") == "zh_Hant"
+        assert normalize_locale("en") == "en"
+
+    def test_none_returns_default(self):
+        assert normalize_locale(None) == "zh"
+
+    def test_zh_cn_maps_to_zh(self):
+        assert normalize_locale("zh_CN") == "zh"
+        assert normalize_locale("zh_Hans") == "zh"
+
+    def test_zh_tw_maps_to_hant(self):
+        assert normalize_locale("zh_TW") == "zh_Hant"
+        assert normalize_locale("zh-Hant") == "zh_Hant"
+
+    def test_unknown_returns_default(self):
+        assert normalize_locale("fr") == "zh"
+        assert normalize_locale("ja") == "zh"
+
+
+class TestListNotificationsI18n:
+    @pytest.mark.asyncio
+    async def test_locale_en_returns_english(
+        self, service: NotificationService, fake_repo: _FakeNotificationRepository
+    ):
+        un, n = _make_notification(
+            user_id=USER_A,
+            title={"zh": "你好", "en": "Hello"},
+            body={"zh": "正文", "en": "Body"},
+        )
+        fake_repo.add_item(un, n)
+
+        result = await service.list_notifications(user_id=USER_A, locale="en")
+        assert result.items[0].title == "Hello"
+        assert result.items[0].body == "Body"
+
+    @pytest.mark.asyncio
+    async def test_locale_zh_hant_falls_back_to_zh(
+        self, service: NotificationService, fake_repo: _FakeNotificationRepository
+    ):
+        un, n = _make_notification(
+            user_id=USER_A,
+            title={"zh": "你好", "en": "Hello"},
+            body={"zh": "正文", "en": "Body"},
+        )
+        fake_repo.add_item(un, n)
+
+        result = await service.list_notifications(user_id=USER_A, locale="zh_Hant")
+        assert result.items[0].title == "你好"
+        assert result.items[0].body == "正文"