feat(telegram): ADR-050 P2 - detail/history info actions 實作

- _send_incident_detail: 取得事件詳情 + AI 信心條形圖，傳送新訊息保留原始簽核卡片
- _send_incident_history: 頻率統計 (1h/24h/7d/30d + 自動修復次數)
- reanalyze: 保留為開發中 placeholder

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

apps/api/src/services/telegram_gateway.py

@@ -1808,10 +1808,23 @@ class TelegramGateway:
             if parsed.get("is_info_action"):
                 if not self._security.is_whitelisted(user_id):
                     raise UserNotWhitelistedError(f"User {user_id} not in whitelist")
-                await self._answer_callback(
-                    callback_query_id, action,
-                    text={"detail": "📋 功能開發中", "reanalyze": "🔄 功能開發中", "history": "📊 功能開發中"}.get(action, "⏳ 功能開發中"),
-                )
+
+                incident_id = parsed.get("incident_id", approval_id)
+
+                if action == "detail":
+                    # ADR-050 P2: 取得事件詳情，傳送新訊息 (保留原始簽核卡片+按鈕)
+                    # 2026-04-01 Claude Code (ADR-050 P2)
+                    await self._answer_callback(callback_query_id, action, text="📋 詳情傳送中...")
+                    await self._send_incident_detail(incident_id)
+                elif action == "history":
+                    # ADR-050 P2: 取得頻率統計
+                    # 2026-04-01 Claude Code (ADR-050 P2)
+                    await self._answer_callback(callback_query_id, action, text="📊 歷史統計傳送中...")
+                    await self._send_incident_history(incident_id)
+                else:
+                    # reanalyze: 開發中
+                    await self._answer_callback(callback_query_id, action, text="🔄 功能開發中")
+
                 return {
                     "action": action,
                     "approval_id": approval_id,
@@ -2225,6 +2238,113 @@ class TelegramGateway:
             "disable_web_page_preview": True,
         })
 
+    async def _send_incident_detail(self, incident_id: str) -> None:
+        """
+        ADR-050 P2: 傳送事件詳情訊息 (不修改原始簽核卡片)
+
+        2026-04-01 Claude Code (ADR-050 P2): detail button handler
+        """
+        # 延遲 import 避免循環依賴 (與 approval_service 同一模式)
+        from src.repositories.incident_repository import get_incident_repository
+
+        try:
+            repo = get_incident_repository()
+            incident = await repo.get_by_id(incident_id)
+
+            if not incident:
+                await self.send_notification(f"⚠️ 找不到事件 <code>{html.escape(incident_id)}</code>")
+                return
+
+            dc = incident.decision_chain
+            confidence_bar = "█" * int((dc.confidence if dc else 0) * 10) + "░" * (10 - int((dc.confidence if dc else 0) * 10))
+
+            lines = [
+                f"📋 <b>事件詳情</b>",
+                f"",
+                f"🔖 <b>ID:</b> <code>{html.escape(incident.incident_id)}</code>",
+                f"📊 <b>狀態:</b> {incident.status.value}",
+                f"⚡ <b>嚴重度:</b> {incident.severity.value}",
+            ]
+
+            if incident.affected_services:
+                lines.append(f"🎯 <b>受影響服務:</b> {', '.join(html.escape(s) for s in incident.affected_services[:3])}")
+
+            if dc:
+                lines += [
+                    f"",
+                    f"🤖 <b>AI 分析</b> ({html.escape(dc.model_used)})",
+                    f"💡 {html.escape(dc.hypothesis[:200])}{'...' if len(dc.hypothesis) > 200 else ''}",
+                    f"📈 信心: [{confidence_bar}] {dc.confidence:.0%}",
+                ]
+                if dc.probable_root_causes:
+                    lines.append(f"🔍 根因: {html.escape(dc.probable_root_causes[0][:100])}")
+
+            lines += [
+                f"",
+                f"🕐 <b>建立:</b> {incident.created_at.strftime('%m/%d %H:%M')}",
+            ]
+
+            if incident.frequency_stats:
+                fs = incident.frequency_stats
+                lines.append(f"📉 <b>頻率:</b> 1h={fs.count_1h} 24h={fs.count_24h} 7d={fs.count_7d}")
+
+            await self.send_notification("\n".join(lines))
+
+        except Exception as e:
+            logger.warning("send_incident_detail_failed", incident_id=incident_id, error=str(e))
+            await self.send_notification(f"⚠️ 無法取得事件詳情: {html.escape(str(e)[:100])}")
+
+    async def _send_incident_history(self, incident_id: str) -> None:
+        """
+        ADR-050 P2: 傳送事件頻率統計訊息
+
+        2026-04-01 Claude Code (ADR-050 P2): history button handler
+        """
+        from src.repositories.incident_repository import get_incident_repository
+
+        try:
+            repo = get_incident_repository()
+            incident = await repo.get_by_id(incident_id)
+
+            if not incident:
+                await self.send_notification(f"⚠️ 找不到事件 <code>{html.escape(incident_id)}</code>")
+                return
+
+            fs = incident.frequency_stats
+            if not fs:
+                await self.send_notification(
+                    f"📊 <b>事件歷史</b>\n\n🔖 <code>{html.escape(incident.incident_id)}</code>\n\n無頻率統計資料"
+                )
+                return
+
+            lines = [
+                f"📊 <b>事件歷史統計</b>",
+                f"",
+                f"🔖 <code>{html.escape(incident.incident_id)}</code>",
+                f"🔑 告警鍵: <code>{html.escape(fs.anomaly_key[:60])}</code>",
+                f"",
+                f"⏱ <b>發生頻率</b>",
+                f"  1小時: {fs.count_1h} 次",
+                f"  24小時: {fs.count_24h} 次",
+                f"  7天: {fs.count_7d} 次",
+                f"  30天: {fs.count_30d} 次",
+            ]
+
+            if fs.auto_repair_count > 0:
+                lines += [
+                    f"",
+                    f"🔧 <b>自動修復</b>",
+                    f"  執行次數: {fs.auto_repair_count}",
+                ]
+                if fs.last_repair_action:
+                    lines.append(f"  最後動作: {html.escape(fs.last_repair_action[:80])}")
+
+            await self.send_notification("\n".join(lines))
+
+        except Exception as e:
+            logger.warning("send_incident_history_failed", incident_id=incident_id, error=str(e))
+            await self.send_notification(f"⚠️ 無法取得歷史統計: {html.escape(str(e)[:100])}")
+
     async def send_notification(
         self,
         text: str,