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/api-client/package.json

@@ -0,0 +1,42 @@
+{
+  "name": "@effigenix/api-client",
+  "version": "0.1.0",
+  "description": "HTTP client for the Effigenix ERP API",
+  "type": "module",
+  "main": "./dist/index.js",
+  "types": "./dist/index.d.ts",
+  "exports": {
+    ".": {
+      "types": "./dist/index.d.ts",
+      "default": "./dist/index.js"
+    }
+  },
+  "scripts": {
+    "build": "tsup",
+    "dev": "tsup --watch",
+    "typecheck": "tsc --noEmit",
+    "clean": "rm -rf dist .turbo",
+    "test": "vitest run",
+    "test:watch": "vitest"
+  },
+  "dependencies": {
+    "@effigenix/config": "workspace:*",
+    "@effigenix/types": "workspace:*",
+    "axios": "^1.6.7"
+  },
+  "devDependencies": {
+    "@types/node": "^20.11.0",
+    "tsup": "^8.0.1",
+    "typescript": "^5.3.3",
+    "vitest": "^1.2.2",
+    "axios-mock-adapter": "^1.22.0"
+  },
+  "tsup": {
+    "entry": ["src/index.ts"],
+    "format": ["esm"],
+    "dts": true,
+    "clean": true,
+    "sourcemap": true,
+    "splitting": false
+  }
+}