feat(C-02)：工具热榜周榜+最近使用

新增ToolUsageRecord使用日志（tool+created_at索引）；/tool/top/总榜按累计排序、周榜按近7天聚合（无日志回退总榜，兼容period旧参）；/tool/recent/登录去重倒序；seed新增AI图片放大/代码运行两个工具。

tool/urls.py

@@ -12,6 +12,8 @@ from .views import (
     ToolFavoriteToggleView,
     ToolFavoriteListView,
     ToolUsageIncrementView,
+    ToolTopView,
+    ToolRecentView,
 )
 from .views.color_history_view import (
     ColorHistoryListView,
@@ -33,6 +35,8 @@ urlpatterns = [
     path('favorites/<int:pk>/toggle/', ToolFavoriteToggleView.as_view()),
     path('favorites/list/', ToolFavoriteListView.as_view()),
     path('usage/<int:pk>/increment/', ToolUsageIncrementView.as_view()),
+    path('top/', ToolTopView.as_view()),
+    path('recent/', ToolRecentView.as_view()),
     path('color-history/', ColorHistoryListView.as_view()),
     path('color-history/<int:pk>/', ColorHistoryDetailView.as_view()),
     path('color-history/clear/', ColorHistoryClearView.as_view()),