feat: add balance display, user columns, device mgmt and sessions for agent

- Backend: add balance to agent stats API
- Backend: return full user details (balance, expiry, online_status, device_count, application) in agent users API
- Backend: export admin device/session handlers, add agent routes for devices and sessions
- Backend: add card type permission check and balance deduction for agent user creation
- Backend: extract checkAgentUserPermission helper, add user edit API
- Frontend: add balance card to agent dashboard
- Frontend: add application, online_status, device_count, balance, expiry_at columns to agent user table
- Frontend: add agent devices page (reuse admin data-table component)
- Frontend: add agent sessions page (reuse admin data-table component)
- Frontend: add devices and sessions to agent navigation and routes
- Add i18n keys for agent devices, sessions, user columns, dashboard balance

backend/internal/router/admin/devices.go

@@ -22,22 +22,22 @@ type DeviceWithDetails struct {
 func SetupDeviceRoutes(r *gin.RouterGroup) {
 	devices := r.Group("/devices")
 	{
-		devices.GET("", handleGetDevices)
-		devices.PUT("/:id/status", handleUpdateDeviceStatus)
-		devices.DELETE("/:id", handleUnbindDevice)
-		devices.DELETE("/batch", handleBatchUnbindDevices)
-		devices.POST("/batch/status", handleBatchUpdateDeviceStatus)
-		devices.POST("/:id/force-offline", handleForceOfflineDevice)
+		devices.GET("", HandleGetDevices)
+		devices.PUT("/:id/status", HandleUpdateDeviceStatus)
+		devices.DELETE("/:id", HandleUnbindDevice)
+		devices.DELETE("/batch", HandleBatchUnbindDevices)
+		devices.POST("/batch/status", HandleBatchUpdateDeviceStatus)
+		devices.POST("/:id/force-offline", HandleForceOfflineDevice)
 	}
 
 	sessions := r.Group("/sessions")
 	{
-		sessions.GET("", handleGetSessions)
-		sessions.DELETE("/:id", handleDeleteSession)
+		sessions.GET("", HandleGetSessions)
+		sessions.DELETE("/:id", HandleDeleteSession)
 	}
 }
 
-func handleGetDevices(c *gin.Context) {
+func HandleGetDevices(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	log.Printf("[DEBUG] handleGetDevices called, userID: %d", userID)
 
@@ -180,7 +180,7 @@ func handleGetDevices(c *gin.Context) {
 	})
 }
 
-func handleUpdateDeviceStatus(c *gin.Context) {
+func HandleUpdateDeviceStatus(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	deviceID := c.Param("id")
 
@@ -221,7 +221,7 @@ func handleUpdateDeviceStatus(c *gin.Context) {
 	response.Success(c, device)
 }
 
-func handleUnbindDevice(c *gin.Context) {
+func HandleUnbindDevice(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	deviceID := c.Param("id")
 
@@ -257,7 +257,7 @@ func handleUnbindDevice(c *gin.Context) {
 	response.Success(c, nil)
 }
 
-func handleBatchUnbindDevices(c *gin.Context) {
+func HandleBatchUnbindDevices(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	var req struct {
 		DeviceIDs []uint `json:"device_ids"`
@@ -303,7 +303,7 @@ func handleBatchUnbindDevices(c *gin.Context) {
 	response.Success(c, nil)
 }
 
-func handleBatchUpdateDeviceStatus(c *gin.Context) {
+func HandleBatchUpdateDeviceStatus(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	var req struct {
 		DeviceIDs []uint `json:"device_ids"`
@@ -356,7 +356,7 @@ type SessionWithDetails struct {
 	IsOnline   bool   `json:"is_online"`
 }
 
-func handleGetSessions(c *gin.Context) {
+func HandleGetSessions(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	deviceIDFilter := c.Query("device_id")
 	appIDFilter := c.Query("app_id")
@@ -478,7 +478,7 @@ func handleGetSessions(c *gin.Context) {
 	response.Success(c, gin.H{"sessions": sessionsWithDetails, "total": total, "page": page, "page_size": pageSize})
 }
 
-func handleDeleteSession(c *gin.Context) {
+func HandleDeleteSession(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	sessionID := c.Param("id")
 
@@ -529,7 +529,7 @@ func handleDeleteSession(c *gin.Context) {
 	response.Success(c, nil)
 }
 
-func handleForceOfflineDevice(c *gin.Context) {
+func HandleForceOfflineDevice(c *gin.Context) {
 	userID := c.GetUint("user_id")
 	deviceID := c.Param("id")
 

backend/internal/router/admin/users.go

@@ -47,7 +47,7 @@ func SetupUserRoutes(r *gin.RouterGroup) {
 		appUsers.PUT("/:id", handleUpdateUser)
 		appUsers.DELETE("/:id", handleDeleteUser)
 		appUsers.GET("/:id/devices", handleGetUserDevices)
-		appUsers.DELETE("/:id/devices/:deviceId", handleUnbindDevice)
+		appUsers.DELETE("/:id/devices/:deviceId", HandleUnbindDevice)
 		appUsers.PUT("/:id/expiry", handleUpdateExpiry)
 		appUsers.POST("/batch/status", handleBatchUpdateStatus)
 		appUsers.DELETE("/batch", handleBatchDelete)