feat(ops): 添加运维监控配置开关

- 在 .env.example 和 config.example.yaml 中添加 ops.enabled 配置项
- 默认值为 true，保持现有行为
- 当设置为 false 时，左侧栏隐藏运维监控菜单并禁用所有运维监控功能
- 修改后端 GetSettings API，让 ops_monitoring_enabled 受 config.ops.enabled 控制
- 数据清理和预聚合任务默认保持开启状态（通过运维监控设置对话框配置）

deploy/.env.example

@@ -124,6 +124,15 @@ GEMINI_OAUTH_SCOPES=
 # GEMINI_QUOTA_POLICY={"tiers":{"LEGACY":{"pro_rpd":50,"flash_rpd":1500,"cooldown_minutes":30},"PRO":{"pro_rpd":1500,"flash_rpd":4000,"cooldown_minutes":5},"ULTRA":{"pro_rpd":2000,"flash_rpd":0,"cooldown_minutes":5}}}
 GEMINI_QUOTA_POLICY=
 
+# -----------------------------------------------------------------------------
+# Ops Monitoring Configuration (运维监控配置)
+# -----------------------------------------------------------------------------
+# Enable ops monitoring features (background jobs and APIs)
+# 是否启用运维监控功能（后台任务和接口）
+# Set to false to hide ops menu in sidebar and disable all ops features
+# 设置为 false 可在左侧栏隐藏运维监控菜单并禁用所有运维监控功能
+OPS_ENABLED=true
+
 # -----------------------------------------------------------------------------
 # Update Configuration (在线更新配置)
 # -----------------------------------------------------------------------------

deploy/config.example.yaml

@@ -221,6 +221,19 @@ redis:
   # 数据库编号（0-15）
   db: 0
 
+# =============================================================================
+# Ops Monitoring (Optional)
+# 运维监控 (可选)
+# =============================================================================
+ops:
+  # Enable ops monitoring features (background jobs and APIs)
+  # 是否启用运维监控功能（后台任务和接口）
+  # Set to false to hide ops menu in sidebar and disable all ops features
+  # 设置为 false 可在左侧栏隐藏运维监控菜单并禁用所有运维监控功能
+  # Other detailed settings (cleanup, aggregation, etc.) are configured in ops settings dialog
+  # 其他详细设置（数据清理、预聚合等）在运维监控设置对话框中配置
+  enabled: true
+
 # =============================================================================
 # JWT Configuration
 # JWT 配置