Add dashboard and latest logs endpoints for smoke tracking

- Introduced a new API endpoint `GET /api/v1/smoke/dashboard` to retrieve a summary of smoking statistics over a specified date range, including today's count and weekly breakdown.
- Added `GET /api/v1/smoke/logs/latest` endpoint to fetch the most recent smoking logs with a configurable limit.
- Updated the smoke handler and service to support the new functionality, including error handling for date parsing and limit validation.
- Enhanced documentation to reflect the new API endpoints and their usage.

internal/routes/smoke_routes.go

@@ -10,8 +10,10 @@ func registerSmokeRoutes(protected *gin.RouterGroup, smokeHandler *smokehandler.
 	// 戒烟/抽烟记录（与 video 去水印功能在路由前缀上区分开）
 	smoke := protected.Group("/smoke")
 	{
+		smoke.GET("/dashboard", smokeHandler.Dashboard)
 		smoke.POST("/logs", smokeHandler.Create)
 		smoke.GET("/logs", smokeHandler.List)
+		smoke.GET("/logs/latest", smokeHandler.LatestLogs)
 		smoke.GET("/logs/:id", smokeHandler.Get)
 		smoke.PUT("/logs/:id", smokeHandler.Update)
 		smoke.DELETE("/logs/:id", smokeHandler.Delete)