feat: Journal list, category pages, pagination, tokens and pl/en strings

- index and category pages paginate with ?page=N and 404 out of range
- category content renders above the list through the html gate
- related posts fall back to the latest posts
- --journal-* tokens and neutral base styles
- pl/en strings registered only for locales the app enables

app/utils/view.ts

@@ -16,6 +16,22 @@ export interface JournalPostView extends JournalPostDetail {
   content_blocked: boolean
 }
 
+/**
+ * Formats an API timestamp as a long date for `language` (a BCP 47 tag such
+ * as "pl-PL"). UTC on both server and browser, so hydration matches. Returns
+ * "" for a missing or invalid value.
+ */
+export function formatJournalDate(iso: string | null | undefined, language: string): string {
+  if (!iso) return ''
+  const d = new Date(iso)
+  if (Number.isNaN(d.getTime())) return ''
+  try {
+    return new Intl.DateTimeFormat(language || 'en', { dateStyle: 'long', timeZone: 'UTC' }).format(d)
+  } catch {
+    return new Intl.DateTimeFormat('en', { dateStyle: 'long', timeZone: 'UTC' }).format(d)
+  }
+}
+
 export function toPostView(post: JournalPostDetail): JournalPostView {
   const gated = gateJournalHtml(post.content_html)
   return {