🎨 Frontend komplett implementiert

Views:
- Login/Registrierung
- Dashboard mit Stats
- Aufträge (Liste + Detail)
- Mitarbeiterverwaltung
- Verfügbarkeitskalender
- Stundenzettel
- Einstellungen
- Module (Dev-Panel)

Features:
- Vue 3 + Composition API
- TailwindCSS mit Dark Mode
- Pinia State Management
- JWT Auth mit Refresh
- Responsive Design
- Rollen-basierte Navigation

src/api/index.ts

@@ -0,0 +1,106 @@
+const API_URL = import.meta.env.VITE_API_URL || '/api'
+
+interface ApiResponse<T = unknown> {
+  data: T
+  status: number
+}
+
+class ApiClient {
+  private baseUrl: string
+
+  constructor(baseUrl: string) {
+    this.baseUrl = baseUrl
+  }
+
+  private getToken(): string | null {
+    return localStorage.getItem('accessToken')
+  }
+
+  private async request<T>(
+    method: string,
+    endpoint: string,
+    data?: unknown
+  ): Promise<ApiResponse<T>> {
+    const headers: Record<string, string> = {
+      'Content-Type': 'application/json',
+    }
+
+    const token = this.getToken()
+    if (token) {
+      headers['Authorization'] = `Bearer ${token}`
+    }
+
+    const config: RequestInit = {
+      method,
+      headers,
+    }
+
+    if (data) {
+      config.body = JSON.stringify(data)
+    }
+
+    const response = await fetch(`${this.baseUrl}${endpoint}`, config)
+    
+    // Handle 401 - try to refresh token
+    if (response.status === 401) {
+      const refreshed = await this.tryRefreshToken()
+      if (refreshed) {
+        // Retry request with new token
+        headers['Authorization'] = `Bearer ${this.getToken()}`
+        const retryResponse = await fetch(`${this.baseUrl}${endpoint}`, {
+          ...config,
+          headers,
+        })
+        const retryData = await retryResponse.json()
+        return { data: retryData, status: retryResponse.status }
+      }
+    }
+
+    const responseData = await response.json()
+
+    if (!response.ok) {
+      throw new Error(responseData.error || 'Request failed')
+    }
+
+    return { data: responseData, status: response.status }
+  }
+
+  private async tryRefreshToken(): Promise<boolean> {
+    const refreshToken = localStorage.getItem('refreshToken')
+    if (!refreshToken) return false
+
+    try {
+      const response = await fetch(`${this.baseUrl}/auth/refresh`, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ refreshToken }),
+      })
+
+      if (!response.ok) return false
+
+      const data = await response.json()
+      localStorage.setItem('accessToken', data.accessToken)
+      return true
+    } catch {
+      return false
+    }
+  }
+
+  get<T>(endpoint: string): Promise<ApiResponse<T>> {
+    return this.request<T>('GET', endpoint)
+  }
+
+  post<T>(endpoint: string, data?: unknown): Promise<ApiResponse<T>> {
+    return this.request<T>('POST', endpoint, data)
+  }
+
+  put<T>(endpoint: string, data?: unknown): Promise<ApiResponse<T>> {
+    return this.request<T>('PUT', endpoint, data)
+  }
+
+  delete<T>(endpoint: string): Promise<ApiResponse<T>> {
+    return this.request<T>('DELETE', endpoint)
+  }
+}
+
+export const api = new ApiClient(API_URL)