refactor(api): remove test_auth.go and inline test helpers

- Export UserIDContextKey in acl.go to allow test access
- Update test_helper.go to use UserIDContextKey directly
- Remove test_auth.go file as functionality is now inlined
- Update all references from userIDContextKey to UserIDContextKey

This simplifies the test helper architecture by eliminating an
unnecessary indirection layer.

server/router/api/v1/acl.go

@@ -23,9 +23,9 @@ import (
 type ContextKey int
 
 const (
-	// userIDContextKey stores the authenticated user's ID in the context.
+	// UserIDContextKey stores the authenticated user's ID in the context.
 	// Set for both session-based and token-based authentication.
-	userIDContextKey ContextKey = iota
+	UserIDContextKey ContextKey = iota
 
 	// sessionIDContextKey stores the session ID in the context.
 	// Only set for session-based authentication (cookie auth).
@@ -59,7 +59,7 @@ func NewGRPCAuthInterceptor(store *store.Store, secret string) *GRPCAuthIntercep
 // 4. Reject: Return 401 Unauthenticated if none of the above succeed
 //
 // On successful authentication, sets context values:
-// - userIDContextKey: The authenticated user's ID (always set)
+// - UserIDContextKey: The authenticated user's ID (always set)
 // - sessionIDContextKey: Session ID (only for cookie auth)
 // - accessTokenContextKey: JWT token (only for Bearer token auth).
 func (in *GRPCAuthInterceptor) AuthenticationInterceptor(ctx context.Context, request any, serverInfo *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (any, error) {
@@ -115,7 +115,7 @@ func (in *GRPCAuthInterceptor) handleAuthenticatedRequest(ctx context.Context, r
 	}
 
 	// Set context values
-	ctx = context.WithValue(ctx, userIDContextKey, user.ID)
+	ctx = context.WithValue(ctx, UserIDContextKey, user.ID)
 
 	if sessionID != "" {
 		// Session-based authentication

server/router/api/v1/auth_service.go

@@ -325,7 +325,7 @@ func (*APIV1Service) buildSessionCookie(ctx context.Context, sessionCookieValue
 }
 
 func (s *APIV1Service) GetCurrentUser(ctx context.Context) (*store.User, error) {
-	userID, ok := ctx.Value(userIDContextKey).(int32)
+	userID, ok := ctx.Value(UserIDContextKey).(int32)
 	if !ok {
 		return nil, nil
 	}

server/router/api/v1/test/test_helper.go

@@ -82,5 +82,5 @@ func (ts *TestService) CreateRegularUser(ctx context.Context, username string) (
 // CreateUserContext creates a context with the given user's ID for authentication.
 func (*TestService) CreateUserContext(ctx context.Context, userID int32) context.Context {
 	// Use the real context key from the parent package
-	return apiv1.CreateTestUserContext(ctx, userID)
+	return context.WithValue(ctx, apiv1.UserIDContextKey, userID)
 }

server/router/api/v1/test_auth.go

@@ -1,19 +0,0 @@
-package v1
-
-import (
-	"context"
-
-	"github.com/usememos/memos/store"
-)
-
-// CreateTestUserContext creates a context with user's ID for testing purposes.
-// This function is only intended for use in tests.
-func CreateTestUserContext(ctx context.Context, userID int32) context.Context {
-	return context.WithValue(ctx, userIDContextKey, userID)
-}
-
-// CreateTestUserContextWithUser creates a context and ensures the user exists for testing.
-// This function is only intended for use in tests.
-func CreateTestUserContextWithUser(ctx context.Context, _ *APIV1Service, user *store.User) context.Context {
-	return context.WithValue(ctx, userIDContextKey, user.ID)
-}