fix(phase34): image_analysis 用正確 bot token 下載 + NemoTron 回覆

- 下載圖片改用 OPENCLAW_TG_BOT_TOKEN（polling bot）
- 結果改用 send_as_nemotron 從 NemoTron bot 回覆到群組

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

apps/api/src/services/image_analysis_service.py

@@ -168,10 +168,11 @@ class ImageAnalysisService:
                 question=question,
             )
             if result:
+                # Phase 34: 用 NemoTron bot 回覆圖片分析結果
                 from src.services.telegram_gateway import get_telegram_gateway
                 tg = get_telegram_gateway()
                 await tg.initialize()
-                await tg.send_text(f"🖼️ <b>圖片分析</b>\n{result}")
+                await tg.send_as_nemotron(f"🖼️ <b>圖片分析</b>\n{result}")
         except Exception as e:
             logger.warning("download_and_analyze_failed", error=str(e))
 
@@ -180,7 +181,8 @@ class ImageAnalysisService:
         try:
             from src.core.config import get_settings
             cfg = get_settings()
-            bot_token = cfg.TELEGRAM_BOT_TOKEN
+            # Phase 34: polling 用 OPENCLAW_TG_BOT_TOKEN 下載圖片
+            bot_token = cfg.OPENCLAW_TG_BOT_TOKEN or cfg.TELEGRAM_BOT_TOKEN
             http = await self._get_http()
 
             # Step 1: getFile → file_path