feat(web): Phase 11 對話式 AI UI/UX (#47-59)

Phase 11.1 對話式容器:
- ConversationalView 雙欄佈局 (左側列表 + 右側詳情)
- ApprovalThreadItem 風險等級 + 相對時間顯示
- SSE 即時更新整合

Phase 11.2 批次處理:
- BatchModeSelector 組件 (全部接受/逐一審核/CRITICAL Only)
- POST /api/v1/approvals/bulk-approve API 端點
- CRITICAL + DESTRUCTIVE 安全過濾 (禁止批次核准)

Phase 11.4 鍵盤快捷鍵:
- useKeyboardShortcuts hook (Y/N/方向鍵/Esc)
- Y 鍵長按 2 秒核准 + 頂部進度指示器
- 快捷鍵說明 Modal (Y/N 高亮顯示)

i18n: 100% next-intl 覆蓋

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

apps/api/src/models/approval.py

@@ -270,3 +270,38 @@ class PendingApprovalsResponse(BaseModel):
     """待簽核清單回應"""
     count: int
     approvals: list[ApprovalRequestResponse]
+
+
+# =============================================================================
+# Phase 11: 批次處理 (Bulk Approval)
+# =============================================================================
+
+class BulkApproveRequest(BaseModel):
+    """
+    批次簽核請求 (Phase 11)
+
+    安全限制:
+    - CRITICAL 風險禁止批次核准
+    - DESTRUCTIVE 資料影響禁止批次核准
+    """
+    approval_ids: list[str] = Field(..., description="要批次簽核的 Approval ID 列表")
+    signer_id: str = Field(..., description="簽核者 ID")
+    signer_name: str = Field(..., description="簽核者名稱")
+    comment: str | None = Field(default=None, description="批次簽核備註")
+
+
+class BulkApproveResult(BaseModel):
+    """單個批次簽核結果"""
+    approval_id: str
+    success: bool
+    message: str
+    execution_triggered: bool = False
+
+
+class BulkApproveResponse(BaseModel):
+    """批次簽核回應"""
+    total: int = Field(..., description="請求處理的總數")
+    succeeded: int = Field(..., description="成功簽核數")
+    failed: int = Field(..., description="失敗數")
+    skipped: int = Field(..., description="跳過數 (CRITICAL/DESTRUCTIVE)")
+    results: list[BulkApproveResult] = Field(..., description="各個 Approval 的處理結果")