feat: Refactor UserController to use UserMapper for DTO conversions

feat: Add ApiErrorDto and ApiValidationErrorDto for standardized error responses

feat: Implement ChangeAvatarRequest, ChangePasswordRequest, ChangeRoleRequest, ChangeStatusRequest, LoginRequest, LoginResponse, and RegisterRequest DTOs

feat: Create custom exceptions for better error handling: BadRequestException, ConflictException, ForbiddenException, NotFoundException, UnauthorizedException, and ValidationException

feat: Add RequestLoggingFilter for logging incoming requests

feat: Implement DevCorsConfig for CORS settings in development environment

feat: Create GlobalExceptionHandler for centralized exception handling

feat: Implement RestAccessDeniedHandler and RestAuthEntryPoint for handling access denied and unauthorized requests

feat: Create CustomPrincipal for Spring Security user details

feat: Implement JwtFilter and JwtService for JWT authentication

feat: Add PasswordGenerator for secure password generation

feat: Implement ServiceAuthFilter for service-level authentication

feat: Create AuthService for handling authentication and password changes

refactor: Update CustomUserDetailsService to use CustomPrincipal

refactor: Update UserService to improve user management and exception handling

fix: Update frontend API base URL in development and production settings

refactor: Clean up Header component and associated CSS

frontend/public/config/settings.dev.json

@@ -1,6 +1,6 @@
 {
   "apiConfig": {
-    "baseUrl": "http://localhost:3000",
+    "baseUrl": "http://localhost:3000/api",
     "endpoints": {
       "auth": {
         "login": "/auth/login",

frontend/public/config/settings.prod.json

@@ -1,6 +1,6 @@
 {
   "apiConfig": {
-    "baseUrl": "http://localhost:3000",
+    "baseUrl": "https://adeptusminiaturium.es/api",
     "endpoints": {
       "auth": {
         "login": "/auth/login",

frontend/src/components/Header.jsx

@@ -6,12 +6,6 @@ const Header = () => {
 
   return (
     <header className="imperial-header py-5 text-center position-relative">
-      <img
-        src="/images/purity.png"
-        alt="Purity Seal"
-        className="purity-seal left"
-      />
-
       <h1 className="mb-2">Adeptus Miniaturium</h1>
       <p className="m-0">{t("header.subtitle")}</p>
     </header>

frontend/src/css/Header.css

@@ -6,28 +6,6 @@ header {
     box-shadow: 0 10px 30px rgba(0,0,0,0.9);
 }
 
-.imperial-header {
-    overflow: visible;
-    z-index: 1000;
-}
-
-.purity-seal {
-    position: absolute;
-    top: 5px;
-    width: 196px;
-    z-index: 10;
-    pointer-events: none;
-}
-
-.purity-seal.left {
-    left: 8%;
-}
-
-.purity-seal.right {
-    right: 5%;
-    transform: rotate(10deg);
-}
-
 header h1 {
     font-family: 'Cinzel', serif;
     font-size: 3.5rem;