fix(platform): 外观主题 - 保证经典黑白主题不可被修改或删除

backend/internal/app/appearance_button_fill_test.go

@@ -47,8 +47,12 @@ func TestAppearanceButtonFillRoundTripAndValidation(t *testing.T) {
 		})
 	}
 	input.SkinThemes[0].Tokens.Buttons.Light.Start = "#000000"
-	if _, err := svc.UpdateAppearance(admin, input); err == nil {
-		t.Fatal("classic fill mutation accepted")
+	overwritten, err := svc.UpdateAppearance(admin, input)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if overwritten.SkinThemes[0].Tokens.Buttons != defaultClassicAppearanceSkin().Tokens.Buttons {
+		t.Fatal("classic fill mutation was stored")
 	}
 }
 

backend/internal/app/appearance_skins.go

@@ -262,11 +262,20 @@ func normalizeAppearanceSkinThemes(themes []AppearanceSkinTheme) []AppearanceSki
 	result := make([]AppearanceSkinTheme, len(themes))
 	copy(result, themes)
 	builtins := defaultAppearanceSkinThemes()
+	classic := defaultClassicAppearanceSkin()
+	replacedClassic := false
 	for index := range result {
 		result[index].ID = strings.ToLower(strings.TrimSpace(result[index].ID))
+		if result[index].ID == defaultAppearanceSkinID {
+			// The system default is not editable. Whatever was submitted is
+			// discarded so a drifted client copy cannot reject the whole save.
+			result[index] = classic
+			replacedClassic = true
+			continue
+		}
 		result[index].Name = strings.TrimSpace(result[index].Name)
 		result[index].Description = strings.TrimSpace(result[index].Description)
-		result[index].Locked = result[index].ID == defaultAppearanceSkinID
+		result[index].Locked = false
 		// Only a wholly absent legacy button block is upgraded. Partial or
 		// malformed submitted parameters remain invalid on the write path.
 		if result[index].Tokens.Buttons == (AppearanceSkinButtons{}) {
@@ -285,6 +294,12 @@ func normalizeAppearanceSkinThemes(themes []AppearanceSkinTheme) []AppearanceSki
 		normalizeAppearanceSkinModeColors(&result[index].Tokens.Dark)
 		result[index].Tokens.Components.ShadowStyle = strings.ToLower(strings.TrimSpace(result[index].Tokens.Components.ShadowStyle))
 	}
+	if !replacedClassic {
+		if len(result) >= maxAppearanceSkinThemes {
+			result = result[:maxAppearanceSkinThemes-1]
+		}
+		result = append([]AppearanceSkinTheme{classic}, result...)
+	}
 	return result
 }
 
@@ -329,8 +344,6 @@ func validateAppearanceSkinThemes(themes []AppearanceSkinTheme, selectedID strin
 	}
 	seen := make(map[string]struct{}, len(themes))
 	foundSelected := false
-	foundClassic := false
-	classic := defaultClassicAppearanceSkin()
 	for _, skin := range themes {
 		if !appearanceSkinIDPattern.MatchString(skin.ID) {
 			return BadAuthRequest("皮肤主题 ID 无效")
@@ -342,12 +355,6 @@ func validateAppearanceSkinThemes(themes []AppearanceSkinTheme, selectedID strin
 		if skin.ID == selectedID {
 			foundSelected = true
 		}
-		if skin.ID == defaultAppearanceSkinID {
-			foundClassic = true
-			if skin.Name != classic.Name || skin.Description != classic.Description || !reflect.DeepEqual(skin.Tokens, classic.Tokens) {
-				return BadAuthRequest("经典黑白为系统默认主题，不能修改或删除")
-			}
-		}
 		if err := validateAppearanceSkinText(skin.Name, "皮肤主题名称", 40, true); err != nil {
 			return err
 		}
@@ -369,9 +376,6 @@ func validateAppearanceSkinThemes(themes []AppearanceSkinTheme, selectedID strin
 			}
 		}
 	}
-	if !foundClassic {
-		return BadAuthRequest("经典黑白为系统默认主题，不能修改或删除")
-	}
 	if !foundSelected {
 		return BadAuthRequest("当前启用的皮肤主题不存在")
 	}

backend/internal/app/appearance_test.go

@@ -452,17 +452,25 @@ func TestAppearanceSkinLibrarySupportsEditableCopiesAndProtectsClassic(t *testin
 		t.Fatalf("custom skin round trip = %#v", updated)
 	}
 
+	classic := defaultClassicAppearanceSkin()
 	withoutClassic := append([]AppearanceSkinTheme(nil), themes[1:]...)
-	_, err = svc.UpdateAppearance(admin, AppearanceSetting{BrandName: "HIMA Studio", BrandSlug: "hima-studio", AuthHeroTitle: defaultAppearanceHeroTitle, SkinID: custom.ID, SkinThemes: withoutClassic})
-	if err == nil || !strings.Contains(err.Error(), "不能修改或删除") {
-		t.Fatalf("missing classic error = %v", err)
+	restored, err := svc.UpdateAppearance(admin, AppearanceSetting{BrandName: "HIMA Studio", BrandSlug: "hima-studio", AuthHeroTitle: defaultAppearanceHeroTitle, SkinID: custom.ID, SkinThemes: withoutClassic})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if restored.SkinThemes[0] != classic {
+		t.Fatalf("missing classic was not restored = %#v", restored.SkinThemes[0])
 	}
 
 	mutatedClassic := append([]AppearanceSkinTheme(nil), themes...)
 	mutatedClassic[0].Name = "改名"
-	_, err = svc.UpdateAppearance(admin, AppearanceSetting{BrandName: "HIMA Studio", BrandSlug: "hima-studio", AuthHeroTitle: defaultAppearanceHeroTitle, SkinID: custom.ID, SkinThemes: mutatedClassic})
-	if err == nil || !strings.Contains(err.Error(), "不能修改或删除") {
-		t.Fatalf("mutated classic error = %v", err)
+	mutatedClassic[0].Tokens.Light.Primary = "#000000"
+	overwritten, err := svc.UpdateAppearance(admin, AppearanceSetting{BrandName: "HIMA Studio", BrandSlug: "hima-studio", AuthHeroTitle: defaultAppearanceHeroTitle, SkinID: custom.ID, SkinThemes: mutatedClassic})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if overwritten.SkinThemes[0] != classic || overwritten.Public.ActiveSkin.ID != custom.ID {
+		t.Fatalf("mutated classic was not overwritten = %#v", overwritten.SkinThemes[0])
 	}
 
 	invalidColor := append([]AppearanceSkinTheme(nil), themes...)

web/src/lib/skin-themes.ts

@@ -336,10 +336,10 @@ export const DEFAULT_CLASSIC_SKIN: SkinDefinition = {
             info: "#2563eb",
             workspace: "#ffffff",
             workspaceGrid: "#f3f3f3",
-            adminBackground: "#f5f5f5",
+            adminBackground: "#f3f4f6",
             adminSurface: "#ffffff",
-            adminSubtle: "#f6f6f6",
-            adminStrong: "#ececec",
+            adminSubtle: "#f7f8fa",
+            adminStrong: "#eceff3",
             authBackground: "#ffffff",
             authPanel: "#f7f7f7",
             authCard: "#ffffff",
@@ -388,9 +388,9 @@ export const DEFAULT_CLASSIC_SKIN: SkinDefinition = {
             info: "#60a5fa",
             workspace: "#181818",
             workspaceGrid: "#222222",
-            adminBackground: "#0f0f0f",
+            adminBackground: "#101010",
             adminSurface: "#181818",
-            adminSubtle: "#222222",
+            adminSubtle: "#202020",
             adminStrong: "#2a2a2a",
             authBackground: "#08090c",
             authPanel: "#0b0c10",