Add frontend git update button and backend update endpoint

server.js

@@ -2,9 +2,12 @@ require('dotenv').config();
 const express = require('express');
 const path = require('path');
 const axios = require('axios');
+const { execFile } = require('child_process');
+const { promisify } = require('util');
 
 const app = express();
 const port = Number(process.env.PORT || 3000);
+const execFileAsync = promisify(execFile);
 
 const lidarrUrl = (process.env.LIDARR_URL || '').replace(/\/$/, '');
 const lidarrApiKey = process.env.LIDARR_API_KEY || '';
@@ -40,6 +43,39 @@ function lidarrHeaders() {
   };
 }
 
+async function runGit(args) {
+  const { stdout } = await execFileAsync('git', args, {
+    cwd: __dirname,
+    timeout: 20000
+  });
+  return String(stdout || '').trim();
+}
+
+async function updateFrontendFromGit() {
+  if (!require('fs').existsSync(path.join(__dirname, '.git'))) {
+    throw new Error('Kein Git-Repository im Container/Projektpfad gefunden.');
+  }
+
+  try {
+    await runGit(['--version']);
+  } catch (_err) {
+    throw new Error('git ist nicht installiert.');
+  }
+
+  const before = await runGit(['rev-parse', '--short', 'HEAD']);
+  const branch = await runGit(['rev-parse', '--abbrev-ref', 'HEAD']);
+  const dirty = await runGit(['status', '--porcelain']);
+  if (dirty) {
+    throw new Error('Lokale Aenderungen vorhanden. Update per Button ist blockiert.');
+  }
+
+  await runGit(['fetch', '--prune', 'origin']);
+  await runGit(['pull', '--ff-only', 'origin', branch]);
+
+  const after = await runGit(['rev-parse', '--short', 'HEAD']);
+  return { before, after, branch, updated: before !== after };
+}
+
 async function lidarrRequest(method, endpoint, data, params) {
   if (!hasLidarrConfig()) {
     throw new Error('Lidarr-Konfiguration unvollstaendig.');
@@ -451,6 +487,15 @@ app.post('/api/lidarr/update-library', async (_req, res) => {
   }
 });
 
+app.post('/api/system/update-frontend', async (_req, res) => {
+  try {
+    const result = await updateFrontendFromGit();
+    res.json({ success: true, ...result });
+  } catch (err) {
+    res.status(500).json({ error: err.message });
+  }
+});
+
 app.get('*', (_req, res) => {
   res.sendFile(path.join(__dirname, 'public', 'index.html'));
 });