refactor(module): simplify module name to Wavelet and standardize import paths

- Declared module Wavelet in backend/go.mod
- Replaced github.com/Rain-kl/Wavelet/ with clean Wavelet/ import paths across backend codebase
- Updated architecture guards, Makefile, swagger, and build tests
- 100% passed all tests, lint checks, and binary compilation

backend/plugins/drivers/driver_asynq_cron/plugin.go

@@ -14,8 +14,8 @@ import (
 
 	"github.com/hibiken/asynq"
 
-	"github.com/Rain-kl/Wavelet/core"
-	"github.com/Rain-kl/Wavelet/plugins/drivers/driver_asynq_worker"
+	"Wavelet/core"
+	"Wavelet/plugins/drivers/driver_asynq_worker"
 )
 
 //go:embed migrations/*.sql

backend/plugins/drivers/driver_asynq_cron/schedule.go

@@ -7,7 +7,7 @@ import (
 	"context"
 	"time"
 
-	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
+	db "Wavelet/plugins/infra/database"
 )
 
 // Schedule 定时任务配置表

backend/plugins/drivers/driver_asynq_cron/scheduler.go

@@ -13,8 +13,8 @@ import (
 
 	"github.com/hibiken/asynq"
 
-	"github.com/Rain-kl/Wavelet/pkg/logger"
-	"github.com/Rain-kl/Wavelet/plugins/drivers/driver_asynq_worker"
+	"Wavelet/pkg/logger"
+	"Wavelet/plugins/drivers/driver_asynq_worker"
 )
 
 var (