refactor(api): Phase A P1 快速勝利 (3 項)

1. 常數提取: SSE_DELAY_SECONDS, MAX_APPROVAL_DISPLAY
2. 錯誤訊息安全化: sanitize_error_message() 移除敏感資訊
3. CI/CD alertname 配置化: is_cicd_alertname() 函數

首席架構師審查 P1 改進 (非阻塞)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api/src/services/terminal_service.py

@@ -20,6 +20,12 @@ import uuid
 from enum import Enum
 from typing import Protocol, runtime_checkable
 
+from src.core.constants import (
+    ERROR_MESSAGE_DISPLAY_LENGTH,
+    MAX_APPROVAL_DISPLAY,
+    SSE_DELAY_SECONDS,
+    sanitize_error_message,
+)
 from src.core.logging import get_logger
 from src.core.sse import EventType, SSEEvent, get_publisher
 from src.models.terminal import (
@@ -511,7 +517,7 @@ class TerminalService:
                 publisher, topic, "Approval-Query", "completed",
                 result={"pending_count": len(pending_approvals)}
             )
-            await asyncio.sleep(0.3)
+            await asyncio.sleep(SSE_DELAY_SECONDS)
 
             if not pending_approvals:
                 await self._publish_thought(
@@ -522,14 +528,15 @@ class TerminalService:
 
             # 顯示待簽核清單摘要
             summary_lines = [f"發現 {len(pending_approvals)} 個待簽核項目:"]
-            for i, approval in enumerate(pending_approvals[:5], 1):  # 最多顯示 5 個
+            for i, approval in enumerate(pending_approvals[:MAX_APPROVAL_DISPLAY], 1):
                 risk = approval.risk_level.value.upper() if approval.risk_level else "UNKNOWN"
                 summary_lines.append(
                     f"  {i}. [{risk}] {approval.action[:50]}"
                 )
 
-            if len(pending_approvals) > 5:
-                summary_lines.append(f"  ... 還有 {len(pending_approvals) - 5} 個")
+            if len(pending_approvals) > MAX_APPROVAL_DISPLAY:
+                remaining = len(pending_approvals) - MAX_APPROVAL_DISPLAY
+                summary_lines.append(f"  ... 還有 {remaining} 個")
 
             await self._publish_thought(
                 publisher, topic, "Executor",
@@ -561,11 +568,11 @@ class TerminalService:
             logger.error("approval_query_failed", error=str(e))
             await self._publish_tool_call(
                 publisher, topic, "Approval-Query", "failed",
-                result={"error": str(e)[:100]}
+                result={"error": sanitize_error_message(str(e))}
             )
             await self._publish_thought(
                 publisher, topic, "System",
-                f"查詢簽核項目失敗: {str(e)[:50]}"
+                f"查詢簽核項目失敗: {sanitize_error_message(str(e), ERROR_MESSAGE_DISPLAY_LENGTH)}"
             )
 
     async def _handle_metrics_query(