Add motivation quote feature to smoking tracking API

- Introduced a new database model `SmokeMotivationQuote` for storing motivational quotes.
- Added a new API endpoint `GET /api/v1/smoke/motivation` to retrieve motivation quotes for users.
- Updated the main.go file to include the new model in the auto-migration process.
- Enhanced smoke_routes.go to register the new motivation route with the smoke handler.

internal/routes/smoke_routes.go

@@ -26,6 +26,7 @@ func registerSmokeRoutes(protected *gin.RouterGroup, smokeHandler *smokehandler.
 		smoke.GET("/logs/:id", smokeHandler.Get)
 		smoke.POST("/logs/:id", smokeHandler.Update)
 		smoke.DELETE("/logs/:id", smokeHandler.Delete)
+		smoke.GET("/motivation", smokeHandler.Motivation)
 
 		// AI 戒烟建议（会员优先；非会员需看广告解锁）
 		smoke.GET("/ai/advice", smokeHandler.GetAIAdvice)