feat(marketing): user profile update, ad placement management, logo limits

- Add PUT /auth/profile endpoint for nickname and avatar updates
- Add ad_placements table and CRUD admin API for managing ad units
- Add GET /marketing/ad-config public API for mini-program to fetch ad config
- Reduce logo limit from 10 to 3 per user, add 2MB file size validation

Made-with: Cursor

cmd/api/main.go

@@ -83,6 +83,7 @@ func main() {
 		&marketingmodel.MarketingTemplate{},
 		&marketingmodel.MarketingDownload{},
 		&marketingmodel.UserLogo{},
+		&marketingmodel.AdPlacement{},
 		&quitcheckinmodel.Profile{},
 		&quitcheckinmodel.DailyStatus{},
 		&quitcheckinmodel.RelapseEvent{},
@@ -166,6 +167,8 @@ func main() {
 	marketingTemplateHandler := marketinghandler.NewTemplateHandler(templateSvc)
 	marketingDownloadHandler := marketinghandler.NewDownloadHandler(downloadSvc)
 	marketingUserLogoHandler := marketinghandler.NewUserLogoHandler(userLogoSvc)
+	adPlacementRepo := marketingrepo.NewAdPlacementRepository(database.DB)
+	marketingAdPlacementHandler := marketinghandler.NewAdPlacementHandler(adPlacementRepo)
 
 	adminService := adminmodule.NewService(
 		database.DB,
@@ -199,6 +202,7 @@ func main() {
 		marketingTemplateHandler,
 		marketingDownloadHandler,
 		marketingUserLogoHandler,
+		marketingAdPlacementHandler,
 		quitCheckinHandler,
 	)