fix(chat): migrate legacy character cache identities

src/data/constants/character_id_aliases.ts

@@ -0,0 +1,14 @@
+const LEGACY_CHARACTER_ID_ALIASES: Readonly<Record<string, string>> =
+  Object.freeze({
+    character_elio: "elio",
+    character_maya: "maya-tan",
+    character_nayeli: "nayeli-cervantes",
+  });
+
+/**
+ * Converts character IDs persisted by pre-catalog releases to the current
+ * backend IDs. Unknown and already-current IDs pass through unchanged.
+ */
+export function normalizeLegacyCharacterId(characterId: string): string {
+  return LEGACY_CHARACTER_ID_ALIASES[characterId] ?? characterId;
+}