refactor(layout): relocate go.mod to backend/ and clean import paths to module root

- Relocated go.mod and go.sum into backend/ root directory
- Stripped redundant backend/ segments from all Go imports (github.com/Rain-kl/Wavelet/...)
- Unified Makefile, swagger, and build-test to execute in backend/ module context
- Ensured 100% build-test, code-check, format, and swagger pass

backend/plugins/domain/auth/audit.go

@@ -8,8 +8,8 @@ import (
 	"context"
 	"encoding/json"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/pkg/logger"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/pkg/logger"
 	"github.com/gin-gonic/gin"
 )
 

backend/plugins/domain/auth/auth_source_resolver.go

@@ -10,8 +10,8 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/database"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
 
 	"github.com/coreos/go-oidc/v3/oidc"
 	"golang.org/x/oauth2"

backend/plugins/domain/auth/cache.go

@@ -10,10 +10,10 @@ import (
 	"sync"
 	"time"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/pkg/cache/ram"
-	"github.com/Rain-kl/Wavelet/backend/pkg/util"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/cache"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/pkg/cache/ram"
+	"github.com/Rain-kl/Wavelet/pkg/util"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/cache"
 )
 
 const (

backend/plugins/domain/auth/cache_test.go

@@ -11,9 +11,9 @@ import (
 	"github.com/redis/go-redis/v9"
 	"github.com/redis/go-redis/v9/maintnotifications"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/plugins/domain/auth"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/cache"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/plugins/domain/auth"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/cache"
 )
 
 func setupOauthCacheTest(t *testing.T) (*miniredis.Miniredis, func()) {

backend/plugins/domain/auth/handlers.go

@@ -13,14 +13,14 @@ import (
 	"strings"
 	"time"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
+	"github.com/Rain-kl/Wavelet/core/contracts"
 
-	"github.com/Rain-kl/Wavelet/backend/pkg/idgen"
-	"github.com/Rain-kl/Wavelet/backend/pkg/logger"
-	"github.com/Rain-kl/Wavelet/backend/pkg/response"
-	"github.com/Rain-kl/Wavelet/backend/pkg/util"
-	cachepkg "github.com/Rain-kl/Wavelet/backend/plugins/infra/cache"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/database"
+	"github.com/Rain-kl/Wavelet/pkg/idgen"
+	"github.com/Rain-kl/Wavelet/pkg/logger"
+	"github.com/Rain-kl/Wavelet/pkg/response"
+	"github.com/Rain-kl/Wavelet/pkg/util"
+	cachepkg "github.com/Rain-kl/Wavelet/plugins/infra/cache"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
 	"github.com/coreos/go-oidc/v3/oidc"
 	"github.com/gin-contrib/sessions"
 	"github.com/gin-gonic/gin"

backend/plugins/domain/auth/middleware.go

@@ -10,11 +10,11 @@ import (
 	"encoding/hex"
 	"errors"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/pkg/response"
-	"github.com/Rain-kl/Wavelet/backend/pkg/trace"
-	"github.com/Rain-kl/Wavelet/backend/pkg/util"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/database"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/pkg/response"
+	"github.com/Rain-kl/Wavelet/pkg/trace"
+	"github.com/Rain-kl/Wavelet/pkg/util"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
 	"github.com/gin-gonic/gin"
 )
 

backend/plugins/domain/auth/models.go

@@ -12,7 +12,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
+	"github.com/Rain-kl/Wavelet/core/contracts"
 )
 
 var authSourceNamePattern = regexp.MustCompile(`^[A-Za-z0-9][A-Za-z0-9_-]{0,79}$`)

backend/plugins/domain/auth/plugin.go

@@ -7,9 +7,9 @@ package auth
 import (
 	"embed"
 
-	"github.com/Rain-kl/Wavelet/backend/core"
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/core/extpoints"
+	"github.com/Rain-kl/Wavelet/core"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/core/extpoints"
 )
 
 //go:embed migrations/*.sql

backend/plugins/domain/auth/plugin_test.go

@@ -16,10 +16,10 @@ import (
 	"github.com/stretchr/testify/require"
 	"gorm.io/gorm"
 
-	"github.com/Rain-kl/Wavelet/backend/core"
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/plugins/domain/auth"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/database"
+	"github.com/Rain-kl/Wavelet/core"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/plugins/domain/auth"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
 )
 
 type testUser struct {

backend/plugins/domain/auth/repository.go

@@ -7,7 +7,7 @@ package auth
 import (
 	"context"
 
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/database"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
 )
 
 // GetAuthSourceByID 根据 ID 获取认证源

backend/plugins/domain/auth/service.go

@@ -8,9 +8,9 @@ import (
 	"errors"
 	"sync"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/pkg/util"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/database"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/pkg/util"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
 	"github.com/gin-gonic/gin"
 )
 

backend/plugins/domain/auth/session.go

@@ -11,9 +11,9 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/Rain-kl/Wavelet/backend/core/contracts"
-	"github.com/Rain-kl/Wavelet/backend/pkg/config"
-	db "github.com/Rain-kl/Wavelet/backend/plugins/infra/database"
+	"github.com/Rain-kl/Wavelet/core/contracts"
+	"github.com/Rain-kl/Wavelet/pkg/config"
+	db "github.com/Rain-kl/Wavelet/plugins/infra/database"
 	"github.com/gin-contrib/sessions"
 	"github.com/gin-gonic/gin"
 	"github.com/google/uuid"