Fix hreflang canonical + LangToggle: use centralized ES/EN slug map

- Add src/i18n/hreflang-map.ts with getHreflangUrl() for translated slugs
- Fix BaseLayout.astro hreflang tags (was hardcoding ES='/', 404 URLs)
- Fix LangToggle.astro to use hreflang map instead of naive path swap
- Fix htaccess.conf: remove !-f / !-d that blocked .html redirects

src/i18n/hreflang-map.ts

@@ -0,0 +1,44 @@
+import type { Lang } from './ui';
+
+const esToEnOverrides: Record<string, string | null> = {
+  '/nosotros/': '/en/about/',
+  '/contacto/': '/en/contact/',
+  '/planes/': '/en/plans/',
+  '/instructivos/': '/en/tutorials/',
+  '/legal/privacidad/': '/en/legal/privacy/',
+  '/legal/terminos/': '/en/legal/terms/',
+  '/preguntas/': null,
+};
+
+const enToEsMap: Record<string, string> = {};
+for (const [esPath, enPath] of Object.entries(esToEnOverrides)) {
+  if (enPath) enToEsMap[enPath] = esPath;
+}
+
+const SITE_URL = 'https://hostingdelsur.net';
+
+export function getHreflangUrl(
+  pathname: string,
+  currentLang: Lang,
+  targetLang: Lang
+): string | null {
+  if (currentLang === targetLang) {
+    return `${SITE_URL}${pathname}`;
+  }
+
+  if (currentLang === 'es' && targetLang === 'en') {
+    const override = esToEnOverrides[pathname];
+    if (override === null) return null;
+    if (override) return `${SITE_URL}${override}`;
+    return `${SITE_URL}/en${pathname}`;
+  }
+
+  if (currentLang === 'en' && targetLang === 'es') {
+    const override = enToEsMap[pathname];
+    if (override) return `${SITE_URL}${override}`;
+    const esPath = pathname.replace(/^\/en/, '') || '/';
+    return `${SITE_URL}${esPath}`;
+  }
+
+  return null;
+}