docs(api): align OpenAPI with runtime contracts (#6409)

Document the cookie-authenticated WebSocket upgrade and its emitted envelopes without exporting pseudo-paths. Align REST response schemas, paged-client filters, and subscription HEAD operations with their runtime implementations, then regenerate frontend and docs artifacts.

internal/xray/traffic.go

@@ -3,9 +3,9 @@ package xray
 // Traffic represents network traffic statistics for Xray connections.
 // It tracks upload and download bytes for inbound or outbound traffic.
 type Traffic struct {
-	IsInbound  bool
-	IsOutbound bool
-	Tag        string
-	Up         int64
-	Down       int64
+	IsInbound  bool   `json:"IsInbound" example:"true"`
+	IsOutbound bool   `json:"IsOutbound" example:"false"`
+	Tag        string `json:"Tag" example:"inbound-443"`
+	Up         int64  `json:"Up" example:"1048576"`
+	Down       int64  `json:"Down" example:"2097152"`
 }