fix(telegram): 修復所有 webhook 路徑缺失 ai_provider → Telegram 顯示「AI 仲裁判定」

根本原因: send_approval_card() 有 ai_provider 參數，但三個 webhook 呼叫端都沒傳:
- signoz_webhook.py: 有 ai_provider 參數但未轉傳給 send_approval_card
- sentry_webhook.py: 有 analysis.analyzed_by 但未傳
- webhooks.py: _push_to_telegram_background 缺少 ai_provider 參數

修復後 Telegram 會顯示「🤖 OpenClaw Nemo 仲裁」而非「🤖 AI 仲裁判定」

2026-04-02 ogt: 三個 webhook 路徑統一修復

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/api/src/api/v1/sentry_webhook.py

@@ -447,6 +447,8 @@ async def send_sentry_telegram_alert(
             confidence=analysis.confidence if analysis else 0.0,
             namespace="sentry",
             anomaly_frequency=anomaly_frequency,
+            # 2026-04-02 ogt: 修復 ai_provider 未傳遞 → Telegram 顯示「AI 仲裁判定」而非具體模型名稱
+            ai_provider=analysis.analyzed_by if analysis else "",
         )
 
         logger.info(