Feat: [2.0.5] 에러 발생 시 Discord 알림 전송

- 요약 처리 중 에러 발생 시 Discord에 에러 상세 내용 전송
- 에러 타입, 메시지, 영상 정보를 포함한 embed 형식

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

app/main.py

@@ -2,7 +2,7 @@ from fastapi import FastAPI, Header, HTTPException
 from pydantic import BaseModel
 
 from app.config import settings
-from app.discord import send_to_discord
+from app.discord import send_error_to_discord, send_to_discord
 from app.summarizer import summarize
 from app.transcript import extract_video_id, fetch_transcript
 
@@ -22,11 +22,16 @@ async def summarize_video(
     if settings.api_secret and x_api_secret != settings.api_secret:
         raise HTTPException(status_code=401, detail="Unauthorized")
 
-    video_id = extract_video_id(req.video_url)
-    transcript = fetch_transcript(video_id)
-    title = req.title or video_id
-    summary = summarize(transcript, title)
-    await send_to_discord(title, req.video_url, summary)
+    title = req.title or "제목 없음"
+
+    try:
+        video_id = extract_video_id(req.video_url)
+        transcript = fetch_transcript(video_id)
+        summary = summarize(transcript, title)
+        await send_to_discord(title, req.video_url, summary)
+    except Exception as e:
+        await send_error_to_discord(title, req.video_url, e)
+        raise HTTPException(status_code=500, detail=str(e))
 
     return {"status": "ok", "title": title, "summary_length": len(summary)}