fix: restore clients page functionality

Updated handleGetClients to return UI-compatible data format and implemented handleGetClient/handleUpdateClient endpoints.

internal/server/dashboard.go

@@ -401,7 +401,114 @@ func (s *Server) handleGetClients(c *gin.Context) {
 		c.JSON(http.StatusInternalServerError, ErrorResponse(err.Error()))
 		return
 	}
-	c.JSON(http.StatusOK, SuccessResponse(clients))
+
+	type UIClient struct {
+		ID                 string    `json:"id"`
+		Name               string    `json:"name"`
+		Description        string    `json:"description"`
+		CreatedAt          time.Time `json:"created_at"`
+		LastUsed           *time.Time `json:"last_used"`
+		RequestsCount      int       `json:"requests_count"`
+		TokensCount        int       `json:"tokens_count"`
+		Status             string    `json:"status"`
+		RateLimitPerMinute int       `json:"rate_limit_per_minute"`
+	}
+
+	uiClients := make([]UIClient, len(clients))
+	for i, cl := range clients {
+		status := "active"
+		if !cl.IsActive {
+			status = "disabled"
+		}
+
+		name := ""
+		if cl.Name != nil {
+			name = *cl.Name
+		}
+		desc := ""
+		if cl.Description != nil {
+			desc = *cl.Description
+		}
+
+		// Get last used from tokens
+		var lastUsed *time.Time
+		_ = s.database.Get(&lastUsed, "SELECT MAX(last_used_at) FROM client_tokens WHERE client_id = ?", cl.ClientID)
+
+		uiClients[i] = UIClient{
+			ID:                 cl.ClientID,
+			Name:               name,
+			Description:        desc,
+			CreatedAt:          cl.CreatedAt,
+			LastUsed:           lastUsed,
+			RequestsCount:      cl.TotalRequests,
+			TokensCount:        cl.TotalTokens,
+			Status:             status,
+			RateLimitPerMinute: cl.RateLimitPerMinute,
+		}
+	}
+
+	c.JSON(http.StatusOK, SuccessResponse(uiClients))
+}
+
+func (s *Server) handleGetClient(c *gin.Context) {
+	id := c.Param("id")
+	var cl db.Client
+	err := s.database.Get(&cl, "SELECT * FROM clients WHERE client_id = ?", id)
+	if err != nil {
+		c.JSON(http.StatusNotFound, ErrorResponse("Client not found"))
+		return
+	}
+
+	name := ""
+	if cl.Name != nil {
+		name = *cl.Name
+	}
+	desc := ""
+	if cl.Description != nil {
+		desc = *cl.Description
+	}
+
+	c.JSON(http.StatusOK, SuccessResponse(gin.H{
+		"id":                     cl.ClientID,
+		"name":                   name,
+		"description":            desc,
+		"is_active":              cl.IsActive,
+		"rate_limit_per_minute":  cl.RateLimitPerMinute,
+		"created_at":             cl.CreatedAt,
+	}))
+}
+
+type UpdateClientRequest struct {
+	Name               string  `json:"name"`
+	Description        *string `json:"description"`
+	IsActive           bool    `json:"is_active"`
+	RateLimitPerMinute *int    `json:"rate_limit_per_minute"`
+}
+
+func (s *Server) handleUpdateClient(c *gin.Context) {
+	id := c.Param("id")
+	var req UpdateClientRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, ErrorResponse("Invalid request"))
+		return
+	}
+
+	_, err := s.database.Exec(`
+		UPDATE clients SET 
+			name = ?, 
+			description = ?, 
+			is_active = ?, 
+			rate_limit_per_minute = COALESCE(?, rate_limit_per_minute),
+			updated_at = CURRENT_TIMESTAMP
+		WHERE client_id = ?
+	`, req.Name, req.Description, req.IsActive, req.RateLimitPerMinute, id)
+
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, ErrorResponse(err.Error()))
+		return
+	}
+
+	c.JSON(http.StatusOK, SuccessResponse(gin.H{"message": "Client updated"}))
 }
 
 type CreateClientRequest struct {
@@ -676,7 +783,7 @@ func (s *Server) handleTestProvider(c *gin.Context) {
 	
 	// Prepare a simple test request
 	testReq := &models.UnifiedRequest{
-		Model: "gpt-4o-mini", // Default cheap test model for OpenAI
+		Model: "gpt-4o-mini", // Default cheap test model
 		Messages: []models.UnifiedMessage{
 			{
 				Role:    "user",