fix(phase34): polling loop 補圖片路由 — _handle_chat_message photo handler

text=None 時直接 return，導致圖片訊息被丟棄
在 text 檢查前插入 photo 路由，呼叫 image_analysis_service

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

apps/api/src/services/telegram_gateway.py

@@ -3542,6 +3542,26 @@ class TelegramGateway:
         message_id = message.get("message_id")
         username = user.get("username") or user.get("first_name") or str(user_id)
 
+        # Phase 34 (ADR-067 2026-04-10): 圖片訊息路由
+        photos = message.get("photo")
+        if photos and user_id:
+            if not user.get("is_bot"):
+                best = max(photos, key=lambda p: p.get("file_size", 0))
+                file_id = best.get("file_id", "")
+                caption = message.get("caption", "請用繁體中文描述這張圖片")
+                if file_id:
+                    try:
+                        from src.services.image_analysis_service import get_image_analysis_service
+                        svc = get_image_analysis_service()
+                        await svc.download_and_analyze(
+                            chat_id=str(chat_id),
+                            file_id=file_id,
+                            question=caption,
+                        )
+                    except Exception as _img_err:
+                        logger.warning("image_analysis_polling_failed", error=str(_img_err))
+            return
+
         if not text or not user_id:
             return