fix(registry): Reset client status on model re-registration

When a client re-registers with the model registry, its previous status for a given model (e.g., quota exceeded or suspended) was not being cleared. This could lead to a situation where a client is permanently unable to use a model even after re-registering.

This change ensures that when a client re-registers an existing model, its ID is removed from the model's `QuotaExceededClients` and `SuspendedClients` lists. This effectively resets the client's status for that model, allowing for a fresh start upon reconnection.

internal/registry/model_registry.go

@@ -237,6 +237,12 @@ func (r *ModelRegistry) RegisterClient(clientID, clientProvider string, models [
 		if reg, ok := r.models[id]; ok {
 			reg.Info = cloneModelInfo(model)
 			reg.LastUpdated = now
+			if reg.QuotaExceededClients != nil {
+				delete(reg.QuotaExceededClients, clientID)
+			}
+			if reg.SuspendedClients != nil {
+				delete(reg.SuspendedClients, clientID)
+			}
 			if providerChanged && provider != "" {
 				if _, newlyAdded := addedSet[id]; newlyAdded {
 					continue