feat: add robots.txt and sitemap.xml routes for SEO optimization

- Implemented a new route for robots.txt to control crawler access.
- Added a sitemap.xml route to provide search engines with a list of site URLs.
- Included functions for URL normalization and XML escaping to ensure proper formatting.

server/routes/robots.txt.js

@@ -0,0 +1,30 @@
+function normalizeBaseUrl(value) {
+  const raw = String(value || '').trim()
+  if (!raw) return ''
+  return raw.replace(/\/+$/, '')
+}
+
+export default defineEventHandler((event) => {
+  const runtimeConfig = useRuntimeConfig(event)
+  const requestUrl = getRequestURL(event)
+
+  const baseUrl = normalizeBaseUrl(runtimeConfig.public?.baseUrl) || `${requestUrl.protocol}//${requestUrl.host}`
+
+  const lines = [
+    'User-agent: *',
+    'Allow: /',
+    'Disallow: /cms',
+    'Disallow: /cms/',
+    'Disallow: /mitgliederbereich',
+    'Disallow: /mitgliederbereich/',
+    'Disallow: /api/',
+    'Disallow: /login',
+    'Disallow: /registrieren',
+    'Disallow: /passwort-vergessen',
+    'Disallow: /konto-loeschen',
+    `Sitemap: ${baseUrl}/sitemap.xml`
+  ]
+
+  setHeader(event, 'Content-Type', 'text/plain; charset=utf-8')
+  return `${lines.join('\n')}\n`
+})

server/routes/sitemap.xml.js

@@ -0,0 +1,87 @@
+function normalizeBaseUrl(value) {
+  const raw = String(value || '').trim()
+  if (!raw) return ''
+  return raw.replace(/\/+$/, '')
+}
+
+function escapeXml(value) {
+  return String(value)
+    .replace(/&/g, '&')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&apos;')
+}
+
+function toAbsoluteUrl(baseUrl, path) {
+  const normalizedPath = path.startsWith('/') ? path : `/${path}`
+  return `${baseUrl}${normalizedPath}`
+}
+
+export default defineEventHandler((event) => {
+  const runtimeConfig = useRuntimeConfig(event)
+  const requestUrl = getRequestURL(event)
+
+  const baseUrl = normalizeBaseUrl(runtimeConfig.public?.baseUrl) || `${requestUrl.protocol}//${requestUrl.host}`
+  const today = new Date().toISOString().slice(0, 10)
+
+  const routes = [
+    '/',
+    '/kontakt',
+    '/termine',
+    '/mitgliedschaft',
+    '/spielplan',
+    '/mannschaften',
+    '/mannschaften/spielplaene',
+    '/mannschaften/herren',
+    '/mannschaften/damen',
+    '/mannschaften/jugend',
+    '/training',
+    '/training/trainer',
+    '/training/anfaenger',
+    '/vereinsmeisterschaften',
+    '/spielsysteme',
+    '/links',
+    '/vorstand',
+    '/impressum',
+    '/datenschutz',
+    '/tt-regeln',
+    '/ueber-uns',
+    '/geschichte',
+    '/satzung',
+    '/galerie',
+    '/verein/ueber-uns',
+    '/verein/geschichte',
+    '/verein/satzung',
+    '/verein/tt-regeln',
+    '/verein/galerie',
+    '/newsletter/subscribe',
+    '/newsletter/unsubscribe'
+  ]
+
+  const uniqueRoutes = [...new Set(routes)]
+
+  const entries = uniqueRoutes.map((route) => {
+    const loc = escapeXml(toAbsoluteUrl(baseUrl, route))
+    const priority = route === '/' ? '1.0' : '0.7'
+    return [
+      '  <url>',
+      `    <loc>${loc}</loc>`,
+      `    <lastmod>${today}</lastmod>`,
+      '    <changefreq>weekly</changefreq>',
+      `    <priority>${priority}</priority>`,
+      '  </url>'
+    ].join('\n')
+  })
+
+  const xml = [
+    '<?xml version="1.0" encoding="UTF-8"?>',
+    '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">',
+    entries.join('\n'),
+    '</urlset>',
+    ''
+  ].join('\n')
+
+  setHeader(event, 'Content-Type', 'application/xml; charset=utf-8')
+  return xml
+})