feat(frontend): TypeScript-Monorepo mit Terminal-UI für Effigenix ERP

Monorepo-Setup (pnpm workspaces) mit vier shared Packages und einer TUI-App:

Shared Packages:
- @effigenix/types: TypeScript-DTOs (UserDTO, RoleDTO, AuthDTO, Enums)
- @effigenix/config: API-Konfiguration und Shared Constants
- @effigenix/validation: Zod-Schemas für Username, E-Mail und Passwort
- @effigenix/api-client: axios-Client mit JWT-Handling (proaktiver + reaktiver
  Token-Refresh), AuthInterceptor, ErrorInterceptor, Resources für auth/users/roles

TUI (apps/cli, Ink 5 / React):
- Authentication: Login/Logout, Session-Restore beim Start, JWT-Refresh
- User Management: Liste, Anlage (Zod-Inline-Validation), Detailansicht,
  Passwort ändern, Sperren/Entsperren mit ConfirmDialog
- Role Management: Liste, Detailansicht, Zuweisen/Entfernen per RoleSelectList (↑↓)
- UX: SuccessDisplay (Auto-Dismiss 3 s), ConfirmDialog (J/N),
  FormInput mit Inline-Fehlern, StatusBar mit API-URL
- Layout: Fullscreen-Modus (alternate screen buffer), Header mit eingeloggtem User
- Tests: vitest + ink-testing-library (15 Tests)

frontend/packages/config/src/api-config.ts

@@ -0,0 +1,34 @@
+/**
+ * API client configuration
+ */
+
+export interface ApiConfig {
+  baseUrl: string;
+  timeoutMs: number;
+  retries: number;
+}
+
+export const DEFAULT_API_CONFIG: ApiConfig = {
+  baseUrl: 'http://localhost:8080',
+  timeoutMs: 10_000,
+  retries: 1,
+};
+
+export const API_PATHS = {
+  auth: {
+    login: '/api/auth/login',
+    logout: '/api/auth/logout',
+    refresh: '/api/auth/refresh',
+  },
+  users: {
+    base: '/api/users',
+    byId: (id: string) => `/api/users/${id}`,
+    lock: (id: string) => `/api/users/${id}/lock`,
+    unlock: (id: string) => `/api/users/${id}/unlock`,
+    roles: (id: string) => `/api/users/${id}/roles`,
+    password: (id: string) => `/api/users/${id}/password`,
+  },
+  roles: {
+    base: '/api/roles',
+  },
+} as const;