fix: memory persistence + language auto-detection for translation workflow

- Upgrade memory/translation debug logs from debug to warning level
- Auto-detect language preference from extracted memory facts
- Persist language prefs to separate JSON file for reliability
- Add translation detection logging
- Use single linebreaks in translation menu

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

bot.py

@@ -61,6 +61,7 @@ WILDFILES_BASE_URL = os.environ.get("WILDFILES_BASE_URL", "")
 WILDFILES_ORG = os.environ.get("WILDFILES_ORG", "")
 USER_KEYS_FILE = os.environ.get("USER_KEYS_FILE", "/data/user_keys.json")
 MEMORIES_DIR = os.environ.get("MEMORIES_DIR", "/data/memories")
+LANGUAGE_PREFS_FILE = os.environ.get("LANGUAGE_PREFS_FILE", "/data/language_prefs.json")
 MAX_MEMORIES_PER_USER = 50
 
 SYSTEM_PROMPT = """You are a helpful AI assistant in a Matrix chat room.
@@ -220,6 +221,7 @@ class Bot:
         self._pending_connects: dict[str, str] = {}  # matrix_user_id -> device_code
         self._pending_translate: dict[str, dict] = {}  # sender -> {text, detected_lang, room_id}
         self._pending_reply: dict[str, dict] = {}  # sender -> {target_lang}
+        self.language_prefs: dict[str, str] = self._load_language_prefs()  # user_id -> language
 
     @staticmethod
     def _load_user_keys() -> dict[str, str]:
@@ -239,6 +241,23 @@ class Bot:
         except Exception:
             logger.exception("Failed to save user keys")
 
+    @staticmethod
+    def _load_language_prefs() -> dict[str, str]:
+        if os.path.exists(LANGUAGE_PREFS_FILE):
+            try:
+                with open(LANGUAGE_PREFS_FILE) as f:
+                    return json.load(f)
+            except Exception:
+                logger.warning("Failed to load language prefs, starting fresh")
+        return {}
+
+    def _save_language_prefs(self):
+        try:
+            with open(LANGUAGE_PREFS_FILE, "w") as f:
+                json.dump(self.language_prefs, f)
+        except Exception:
+            logger.exception("Failed to save language prefs")
+
     async def start(self):
         # Restore existing session or create new one
         if os.path.exists(CREDS_FILE):
@@ -488,10 +507,21 @@ class Bot:
             for fact in new_facts:
                 if isinstance(fact, str) and fact.strip():
                     existing.append({"fact": fact.strip(), "created": now, "source_room": room_id})
+                    # Auto-detect language preference from new facts
+                    fl = fact.lower()
+                    if "language" in fl or "speaks" in fl or "prefers" in fl:
+                        for lang in ["English", "German", "French", "Spanish", "Italian",
+                                     "Portuguese", "Dutch", "Russian", "Chinese", "Japanese",
+                                     "Korean", "Arabic", "Turkish", "Greek", "Hebrew"]:
+                            if lang.lower() in fl:
+                                self.language_prefs[sender] = lang
+                                self._save_language_prefs()
+                                logger.info("Auto-detected language preference: %s for %s", lang, sender)
+                                break
 
             return existing
         except Exception:
-            logger.debug("Memory extraction failed", exc_info=True)
+            logger.warning("Memory extraction failed", exc_info=True)
             return existing
 
     async def _detect_language(self, text: str) -> str:
@@ -531,7 +561,11 @@ class Bot:
             return f"[Translation failed] {text}"
 
     def _get_preferred_language(self, user_id: str) -> str:
-        """Extract user's preferred language from memories, default English."""
+        """Get user's preferred language from explicit prefs, then memories, default English."""
+        # Check explicit language preference first
+        if user_id in self.language_prefs:
+            return self.language_prefs[user_id]
+        # Fallback: scan memories
         memories = self._load_memories(user_id)
         known_langs = [
             "English", "German", "French", "Spanish", "Italian", "Portuguese",
@@ -639,6 +673,7 @@ class Bot:
         if is_dm and not body.startswith("!ai") and not image_data:
             preferred_lang = self._get_preferred_language(sender)
             detected_lang = await self._detect_language(body)
+            logger.info("Translation check: detected=%s, preferred=%s, len=%d", detected_lang, preferred_lang, len(body))
             if (
                 detected_lang != "Unknown"
                 and detected_lang.lower() != preferred_lang.lower()
@@ -650,7 +685,7 @@ class Bot:
                     "room_id": room.room_id,
                 }
                 menu = (
-                    f"This looks like **{detected_lang}**. What would you like?\n\n"
+                    f"This looks like **{detected_lang}**. What would you like?\n"
                     f"1️⃣ **Translate to {preferred_lang}**\n"
                     f"2️⃣ **Help me reply in {detected_lang}** (type your response, I'll translate)\n"
                     f"3️⃣ **Just respond normally**"
@@ -1181,8 +1216,10 @@ class Bot:
                         self._save_memories(sender, updated)
                         logger.info("Saved %d new memories for %s (total: %d)",
                                     len(updated) - len(memories), sender, len(updated))
+                    else:
+                        logger.info("No new memories extracted for %s", sender)
                 except Exception:
-                    logger.debug("Memory save failed", exc_info=True)
+                    logger.warning("Memory save failed", exc_info=True)
 
             # Auto-rename: only for group rooms with explicit opt-in (not DMs)
             if room.room_id in self.auto_rename_rooms: