Replace composable with Pinia store for persistent auth state

stores/auth.js

@@ -0,0 +1,58 @@
+import { defineStore } from 'pinia'
+
+export const useAuthStore = defineStore('auth', {
+  state: () => ({
+    isLoggedIn: false,
+    user: null,
+    role: null
+  }),
+
+  getters: {
+    isAdmin: (state) => {
+      return state.role === 'admin' || state.role === 'vorstand'
+    }
+  },
+
+  actions: {
+    async checkAuth() {
+      try {
+        const response = await $fetch('/api/auth/status')
+        this.isLoggedIn = response.isLoggedIn
+        this.user = response.user
+        this.role = response.role
+        return response
+      } catch (error) {
+        this.isLoggedIn = false
+        this.user = null
+        this.role = null
+        return { isLoggedIn: false }
+      }
+    },
+
+    async login(email, password) {
+      const response = await $fetch('/api/auth/login', {
+        method: 'POST',
+        body: { email, password }
+      })
+      
+      if (response.success) {
+        await this.checkAuth()
+      }
+      
+      return response
+    },
+
+    async logout() {
+      try {
+        await $fetch('/api/auth/logout', { method: 'POST' })
+        this.isLoggedIn = false
+        this.user = null
+        this.role = null
+      } catch (error) {
+        console.error('Logout fehlgeschlagen:', error)
+        throw error
+      }
+    }
+  }
+})
+