refactor: UI

internal/backend/server/config/legacy_runtime.go

@@ -16,6 +16,7 @@ func (store *Store) LegacyRuntimeSnapshot(ctx context.Context) (legacyruntime.Ru
 	for _, item := range cfg.ModelAdapters {
 		adapters = append(adapters, legacyruntime.ModelAdapterConfig{
 			ID:                          item.ID,
+			Sort:                        item.Sort,
 			DisplayName:                 item.DisplayName,
 			Type:                        item.Type,
 			BaseURL:                     item.BaseURL,

internal/backend/server/config/manager.go

@@ -147,6 +147,7 @@ func (manager *Manager) LegacyRuntimeSnapshot(_ context.Context) (legacyruntime.
 	for _, item := range cfg.ModelAdapters {
 		adapters = append(adapters, legacyruntime.ModelAdapterConfig{
 			ID:                       item.ID,
+			Sort:                     item.Sort,
 			DisplayName:              item.DisplayName,
 			Type:                     item.Type,
 			BaseURL:                  item.BaseURL,

internal/backend/server/config/types.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -21,6 +22,7 @@ const (
 
 type ModelAdapterConfig struct {
 	ID                          string `json:"id,omitempty" yaml:"-"`
+	Sort                        int    `json:"sort" yaml:"sort"`
 	DisplayName                 string `json:"displayName" yaml:"displayName"`
 	Type                        string `json:"type" yaml:"type"`
 	BaseURL                     string `json:"baseURL" yaml:"baseURL"`
@@ -104,6 +106,7 @@ func NormalizeModelAdapterConfigs(input []ModelAdapterConfig) ([]ModelAdapterCon
 		}
 		nextType := normalizeModelAdapterType(item.Type)
 		next := ModelAdapterConfig{
+			Sort:                 item.Sort,
 			DisplayName:          strings.TrimSpace(item.DisplayName),
 			Type:                 nextType,
 			BaseURL:              baseURL,
@@ -164,9 +167,30 @@ func NormalizeModelAdapterConfigs(input []ModelAdapterConfig) ([]ModelAdapterCon
 		seenChannelIDs[next.ID] = struct{}{}
 		normalized = append(normalized, next)
 	}
+	normalizeModelAdapterSorts(normalized)
 	return normalized, nil
 }
 
+func normalizeModelAdapterSorts(adapters []ModelAdapterConfig) {
+	sort.SliceStable(adapters, func(leftIndex, rightIndex int) bool {
+		left := adapters[leftIndex].Sort
+		right := adapters[rightIndex].Sort
+		switch {
+		case left <= 0 && right <= 0:
+			return false
+		case left <= 0:
+			return false
+		case right <= 0:
+			return true
+		default:
+			return left < right
+		}
+	})
+	for index := range adapters {
+		adapters[index].Sort = index + 1
+	}
+}
+
 func validateJSONMap(value string, fieldName string) error {
 	text := strings.TrimSpace(value)
 	if text == "" {

internal/backend/server/config/types_test.go

@@ -0,0 +1,60 @@
+package config
+
+import "testing"
+
+func testModelAdapter(displayName string, sortValue int) ModelAdapterConfig {
+	return ModelAdapterConfig{
+		Sort:            sortValue,
+		DisplayName:     displayName,
+		Type:            "openai",
+		BaseURL:         "https://api.example.com/v1",
+		APIKey:          "test-key",
+		TooltipData:     displayName,
+		ModelID:         displayName,
+		ReasoningEffort: "medium",
+		OpenAIEndpoint:  "/v1/responses",
+	}
+}
+
+func TestNormalizeModelAdapterConfigsPreservesLegacyArrayOrder(t *testing.T) {
+	adapters, err := NormalizeModelAdapterConfigs([]ModelAdapterConfig{
+		testModelAdapter("first", 0),
+		testModelAdapter("second", 0),
+		testModelAdapter("third", 0),
+	})
+	if err != nil {
+		t.Fatalf("NormalizeModelAdapterConfigs returned error: %v", err)
+	}
+
+	for index, expectedName := range []string{"first", "second", "third"} {
+		if adapters[index].DisplayName != expectedName {
+			t.Fatalf("adapter %d = %q, want %q", index, adapters[index].DisplayName, expectedName)
+		}
+		if adapters[index].Sort != index+1 {
+			t.Fatalf("adapter %d sort = %d, want %d", index, adapters[index].Sort, index+1)
+		}
+	}
+}
+
+func TestNormalizeModelAdapterConfigsUsesStableExplicitSort(t *testing.T) {
+	adapters, err := NormalizeModelAdapterConfigs([]ModelAdapterConfig{
+		testModelAdapter("legacy", 0),
+		testModelAdapter("third", 30),
+		testModelAdapter("first", 10),
+		testModelAdapter("second-a", 20),
+		testModelAdapter("second-b", 20),
+	})
+	if err != nil {
+		t.Fatalf("NormalizeModelAdapterConfigs returned error: %v", err)
+	}
+
+	expectedNames := []string{"first", "second-a", "second-b", "third", "legacy"}
+	for index, expectedName := range expectedNames {
+		if adapters[index].DisplayName != expectedName {
+			t.Fatalf("adapter %d = %q, want %q", index, adapters[index].DisplayName, expectedName)
+		}
+		if adapters[index].Sort != index+1 {
+			t.Fatalf("adapter %d sort = %d, want %d", index, adapters[index].Sort, index+1)
+		}
+	}
+}