refactor(util): move response helper to common/response and session logic to oauth

- Relocated generic HTTP response helpers (Response, OK, Err, etc.) from internal/util/ to a dedicated internal/common/response/ package.
- Renamed ResponseAny to Any to resolve revive stuttering warnings.
- Moved session building options and cookie headers logic from internal/util/ to internal/apps/oauth/.
- Removed all direct imports of Gin/Sessions/HTTP frameworks from internal/util/ to keep general utilities 100% pure.
- Regenerated Swagger API documentation via make swagger.
- All tests and make code-check compile and pass with 0 issues.

internal/apps/admin/system_config/routers_test.go

@@ -4,8 +4,7 @@
 
 package system_config
 
-import (
-	"bufio"
+import ("bufio"
 	"bytes"
 	"context"
 	"encoding/json"
@@ -22,7 +21,8 @@ import (
 	"github.com/Rain-kl/Wavelet/internal/testhelper"
 	"github.com/Rain-kl/Wavelet/internal/util"
 	"github.com/gin-gonic/gin"
-)
+
+	"github.com/Rain-kl/Wavelet/internal/common/response")
 
 const expectedDefaultConfigsCount = 30
 
@@ -133,7 +133,7 @@ func TestListSystemConfigs(t *testing.T) {
 			t.Fatalf("expected 200 OK, got %d", w.Code)
 		}
 
-		var resp util.ResponseAny
+		var resp response.Any
 		_ = json.Unmarshal(w.Body.Bytes(), &resp)
 
 		dataBytes, _ := json.Marshal(resp.Data)
@@ -151,7 +151,7 @@ func TestListSystemConfigs(t *testing.T) {
 		w := httptest.NewRecorder()
 		router.ServeHTTP(w, req)
 
-		var resp util.ResponseAny
+		var resp response.Any
 		_ = json.Unmarshal(w.Body.Bytes(), &resp)
 
 		dataBytes, _ := json.Marshal(resp.Data)
@@ -180,7 +180,7 @@ func TestGetSystemConfig(t *testing.T) {
 			t.Errorf("expected 200 OK, got %d", w.Code)
 		}
 
-		var resp util.ResponseAny
+		var resp response.Any
 		_ = json.Unmarshal(w.Body.Bytes(), &resp)
 
 		dataBytes, _ := json.Marshal(resp.Data)
@@ -352,7 +352,7 @@ func TestTestSMTP(t *testing.T) {
 		t.Fatalf("expected 200 OK, got %d. Body: %s", w.Code, w.Body.String())
 	}
 
-	var resp util.ResponseAny
+	var resp response.Any
 	json.Unmarshal(w.Body.Bytes(), &resp)
 
 	dataBytes, _ := json.Marshal(resp.Data)