chore: stabilize pipeline and harden infrastructure

- Harden E2E smoke tests with increased timeouts and German keyword detection
- Implement defensive body parsing in analytics relay to prevent crashes
- Refine middleware to bypass i18n logic for Server Actions
- Fix date formatting consistency and JsonLd validation

app/[locale]/blog/page.tsx

@@ -198,11 +198,14 @@ export default async function BlogIndex({ params }: BlogIndexProps) {
 
                       <div className="flex items-center gap-3 text-xs md:text-sm font-bold text-white/80 mb-3 tracking-widest uppercase">
                         <time dateTime={post.frontmatter.date} suppressHydrationWarning>
-                          {new Date(post.frontmatter.date).toLocaleDateString(locale || 'de', {
-                            year: 'numeric',
-                            month: 'long',
-                            day: 'numeric',
-                          })}
+                          {new Date(post.frontmatter.date).toLocaleDateString(
+                            locale === 'en' ? 'en-US' : 'de-DE',
+                            {
+                              year: 'numeric',
+                              month: 'long',
+                              day: 'numeric',
+                            },
+                          )}
                         </time>
                       </div>