fix: harden Korean-only output lock (front+end, explicit script ban)

qwen2.5:7b leaked Chinese/Cyrillic mid-reply despite the OUTPUT_LANGUAGE
lock, which was buried mid-prompt. Repeat the lock at the END of the system
prompt (recency) and ban specific foreign scripts explicitly.

src/jarvis/reply/engine.py

@@ -1704,6 +1704,12 @@ def run_reply_engine(db: "Database", cfg, tts: Optional[Any],
         # else: tools are passed via the native tools API parameter — do not include tools_desc
         # here as well, since that confuses the model and causes it to not use tools properly.
 
+        # Recency reinforcement: repeat the language lock at the very END too.
+        # In a ~5k-token prompt the front-placed rule gets "lost in the middle";
+        # bigger models (qwen2.5:7b) otherwise leak Chinese/Cyrillic mid-reply.
+        if _lang_directive:
+            guidance.append(_lang_directive)
+
         return "\n".join(guidance)
 
     messages = []  # type: ignore[var-annotated]