feat(access-logs): 接入 User-Agent 与设备/浏览器/状态码分布

- Agent 访问日志上报 user_agent，OpenResty log_format 输出 http_user_agent
- of_node_access_logs 新增 user_agent 列并写入 ClickHouse
- 访问日志概览新增：设备类型饼图、状态码饼图、浏览器/OS/User-Agent 排行
- 日志明细列表增加 User-Agent 列
- 扩展 UA 解析工具（browser/os/device）并支持 CLI 识别

docs/docs.go

@@ -14325,6 +14325,9 @@ const docTemplate = `{
                 },
                 "status_code": {
                     "type": "integer"
+                },
+                "user_agent": {
+                    "type": "string"
                 }
             }
         },
@@ -16232,15 +16235,33 @@ const docTemplate = `{
         "observability.AccessLogOverview": {
             "type": "object",
             "properties": {
+                "device_types": {
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/observability.DistributionItem"
+                    }
+                },
                 "generated_at": {
                     "type": "string"
                 },
                 "hours": {
                     "type": "integer"
                 },
+                "status_codes": {
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/observability.DistributionItem"
+                    }
+                },
                 "summary": {
                     "$ref": "#/definitions/observability.AccessLogOverviewSummary"
                 },
+                "top_browsers": {
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/observability.DistributionItem"
+                    }
+                },
                 "top_hosts": {
                     "type": "array",
                     "items": {
@@ -16253,12 +16274,24 @@ const docTemplate = `{
                         "$ref": "#/definitions/observability.DistributionItem"
                     }
                 },
+                "top_operating_systems": {
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/observability.DistributionItem"
+                    }
+                },
                 "top_paths": {
                     "type": "array",
                     "items": {
                         "$ref": "#/definitions/observability.DistributionItem"
                     }
                 },
+                "top_user_agents": {
+                    "type": "array",
+                    "items": {
+                        "$ref": "#/definitions/observability.DistributionItem"
+                    }
+                },
                 "trends": {
                     "$ref": "#/definitions/observability.AccessLogOverviewTrends"
                 }
@@ -16341,6 +16374,9 @@ const docTemplate = `{
                 },
                 "status_code": {
                     "type": "integer"
+                },
+                "user_agent": {
+                    "type": "string"
                 }
             }
         },