i18n(comments): all UI strings through translations

Pulls every German string out of Comments.svelte, PostCard.svelte and
CommentCountBadge.svelte and routes it through `useTranslate()` +
the `T.*` key registry. New keys (`comments_*`, `post_overview` count
aria, `comments_jump_to`) are registered in `lib/translations.ts`.

Default DE values land in
`cms_content/windwiderstand/de/translation_bundle/app.json5` (committed
separately) so the CMS-loaded bundle keeps the same look without each
component falling back to its raw key.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/lib/translations.ts

@@ -133,6 +133,35 @@ const TRANSLATION_KEYS = [
   "post_map_activate",
   "post_map_open_osm",
   "post_comments",
+  // Comment plugin (Comments.svelte / PostCard count pill / CommentCountBadge).
+  "comments_loading",
+  "comments_load_error_title",
+  "comments_retry",
+  "comments_empty",
+  "comments_edit",
+  "comments_delete",
+  "comments_save",
+  "comments_cancel",
+  "comments_confirm_delete",
+  "comments_reply",
+  "comments_reply_count_one",
+  "comments_reply_count_other",
+  "comments_reply_send",
+  "comments_send",
+  "comments_sending",
+  "comments_form_title",
+  "comments_name_placeholder",
+  "comments_body_placeholder",
+  "comments_reply_placeholder",
+  "comments_approval_hint",
+  "comments_edited",
+  "comments_pending_short",
+  "comments_pending_full",
+  "comments_self_marker",
+  "comments_pending_summary_one",
+  "comments_pending_summary_other",
+  "comments_count_aria",
+  "comments_jump_to",
 ] as const;
 
 export type TranslationKey = (typeof TRANSLATION_KEYS)[number];