fix(i18n): replace hardcoded German edit hint in CommentMessage with Paraglide key

Adds comment_edit_hint key to de/en/es message files and replaces the
hardcoded "Enter speichern · Esc abbrechen" string in CommentMessage.svelte.

Fixes @felixbrandt + @leonievoss: "hardcoded German bypasses Paraglide"

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/messages/de.json

@@ -321,6 +321,7 @@
 	"comment_btn_post": "Senden",
 	"comment_btn_reply": "Antworten",
 	"comment_edited_label": "(Bearbeitet)",
+	"comment_edit_hint": "Enter speichern · Esc abbrechen",
 	"comment_time_just_now": "gerade eben",
 	"comment_time_minutes": "vor {count} Minute(n)",
 	"comment_time_hours": "vor {count} Stunde(n)",

frontend/messages/en.json

@@ -321,6 +321,7 @@
 	"comment_btn_post": "Send",
 	"comment_btn_reply": "Reply",
 	"comment_edited_label": "(Edited)",
+	"comment_edit_hint": "Enter to save · Esc to cancel",
 	"comment_time_just_now": "just now",
 	"comment_time_minutes": "{count} minute(s) ago",
 	"comment_time_hours": "{count} hour(s) ago",

frontend/messages/es.json

@@ -321,6 +321,7 @@
 	"comment_btn_post": "Enviar",
 	"comment_btn_reply": "Responder",
 	"comment_edited_label": "(Editado)",
+	"comment_edit_hint": "Enter para guardar · Esc para cancelar",
 	"comment_time_just_now": "justo ahora",
 	"comment_time_minutes": "hace {count} minuto(s)",
 	"comment_time_hours": "hace {count} hora(s)",

frontend/src/lib/components/CommentMessage.svelte

@@ -70,7 +70,7 @@ const parsed = $derived(extractQuote(message.content));
 				oninput={(e) => onEditTextChange((e.currentTarget as HTMLTextAreaElement).value)}
 				onkeydown={onEditKeydown}
 			></textarea>
-			<div class="mt-1 font-sans text-xs text-ink-3">Enter speichern · Esc abbrechen</div>
+			<div class="mt-1 font-sans text-xs text-ink-3">{m.comment_edit_hint()}</div>
 		{:else}
 			<!-- svelte-ignore a11y_click_events_have_key_events -->
 			<!-- svelte-ignore a11y_no_static_element_interactions -->