feat: add tenant and user management with migrations, handlers, and tests

- Implemented tenant and user management features including:
  - Tenant creation and management with associated migrations.
  - User creation and management with associated migrations.
  - Tenant membership management with associated migrations.
  - Platform user roles management with associated migrations.
  - Quota management with associated migrations.
  - Article and template management with associated migrations.
- Added HTTP handlers for templates and workspaces.
- Created tests for protected and public routes.
- Introduced a script to check tenant scope in SQL queries.
- Documented task plan for backend completion and frontend foundation.

server/internal/shared/response/errors.go

@@ -0,0 +1,35 @@
+package response
+
+import "net/http"
+
+func ErrBadRequest(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusBadRequest, Code: code, Message: message, Detail: detail}
+}
+
+func ErrUnauthorized(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusUnauthorized, Code: code, Message: message, Detail: detail}
+}
+
+func ErrForbidden(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusForbidden, Code: code, Message: message, Detail: detail}
+}
+
+func ErrNotFound(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusNotFound, Code: code, Message: message, Detail: detail}
+}
+
+func ErrConflict(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusConflict, Code: code, Message: message, Detail: detail}
+}
+
+func ErrTooManyRequests(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusTooManyRequests, Code: code, Message: message, Detail: detail}
+}
+
+func ErrInternal(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusInternalServerError, Code: code, Message: message, Detail: detail}
+}
+
+func ErrServiceUnavailable(code int, message, detail string) *AppError {
+	return &AppError{HTTPStatus: http.StatusServiceUnavailable, Code: code, Message: message, Detail: detail}
+}

server/internal/shared/response/response.go

@@ -0,0 +1,70 @@
+package response
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+type AppError struct {
+	HTTPStatus int    `json:"-"`
+	Code       int    `json:"code"`
+	Message    string `json:"message"`
+	Detail     string `json:"detail,omitempty"`
+	Cause      error  `json:"-"`
+}
+
+func (e *AppError) Error() string {
+	if e.Cause != nil {
+		return e.Cause.Error()
+	}
+	return e.Message
+}
+
+func Success(c *gin.Context, data interface{}) {
+	c.JSON(http.StatusOK, gin.H{
+		"code":       0,
+		"message":    "ok",
+		"data":       data,
+		"request_id": getRequestID(c),
+	})
+}
+
+func SuccessWithStatus(c *gin.Context, status int, data interface{}) {
+	c.JSON(status, gin.H{
+		"code":       0,
+		"message":    "ok",
+		"data":       data,
+		"request_id": getRequestID(c),
+	})
+}
+
+func Error(c *gin.Context, err error) {
+	appErr := Normalize(err)
+	c.JSON(appErr.HTTPStatus, gin.H{
+		"code":       appErr.Code,
+		"message":    appErr.Message,
+		"detail":     appErr.Detail,
+		"request_id": getRequestID(c),
+	})
+}
+
+func Normalize(err error) *AppError {
+	if appErr, ok := err.(*AppError); ok {
+		return appErr
+	}
+	return &AppError{
+		HTTPStatus: http.StatusInternalServerError,
+		Code:       50000,
+		Message:    "internal_error",
+		Detail:     err.Error(),
+		Cause:      err,
+	}
+}
+
+func getRequestID(c *gin.Context) string {
+	if rid, ok := c.Get("request_id"); ok {
+		return rid.(string)
+	}
+	return ""
+}