feat(provider): add status and banning mechanism

Introduce fields for managing provider status (active, auto_disabled,
manual_disabled) and banning logic.

- Add Status, AutoBan, BanReason, and BanUntil to Provider model and DTO
- Update CreateProvider handler to process new fields with defaults
- Extend sync service to propagate status and ban information in snapshots
- Serialize BanUntil as Unix timestamp for sync compatibility

internal/api/handler.go

@@ -48,13 +48,29 @@ func (h *Handler) CreateProvider(c *gin.Context) {
 		group = "default"
 	}
 
+	status := strings.TrimSpace(req.Status)
+	if status == "" {
+		status = "active"
+	}
+	autoBan := true
+	if req.AutoBan != nil {
+		autoBan = *req.AutoBan
+	}
+
 	provider := model.Provider{
-		Name:    req.Name,
-		Type:    req.Type,
-		BaseURL: req.BaseURL,
-		APIKey:  req.APIKey,
-		Group:   group,
-		Models:  strings.Join(req.Models, ","),
+		Name:      req.Name,
+		Type:      req.Type,
+		BaseURL:   req.BaseURL,
+		APIKey:    req.APIKey,
+		Group:     group,
+		Models:    strings.Join(req.Models, ","),
+		Status:    status,
+		AutoBan:   autoBan,
+		BanReason: req.BanReason,
+	}
+	if !req.BanUntil.IsZero() {
+		tu := req.BanUntil.UTC()
+		provider.BanUntil = &tu
 	}
 
 	if err := h.db.Create(&provider).Error; err != nil {