站点背景功能优化、页脚上边距调整

backend/service/bg.go

@@ -17,14 +17,11 @@ const (
 	BgSurfaceSite  = "site"
 	BgSurfaceAdmin = "admin"
 
-	BgModeCover    = "cover"
-	BgModeContain  = "contain"
-	BgModeRepeat   = "repeat"
-	BgModeRepeatX  = "repeat-x"
-	BgModeRepeatY  = "repeat-y"
-	BgModeStretch  = "stretch"
-	BgModeCenter   = "center"
-	DefaultBgMode  = BgModeCover
+	BgModeCover   = "cover"
+	BgModeContain = "contain"
+	BgModeRepeat  = "repeat"
+	BgModeStretch = "stretch"
+	DefaultBgMode = BgModeCover
 )
 
 // ErrBgFileMissing 设置了合法 URL 但磁盘上没有对应文件
@@ -37,10 +34,7 @@ var bgModes = map[string]struct{}{
 	BgModeCover:   {},
 	BgModeContain: {},
 	BgModeRepeat:  {},
-	BgModeRepeatX: {},
-	BgModeRepeatY: {},
 	BgModeStretch: {},
-	BgModeCenter:  {},
 }
 
 // NormalizeBgMode 校验铺放模式；空串视为默认 cover

backend/service/bg_test.go

@@ -36,8 +36,13 @@ func TestNormalizeBgMode(t *testing.T) {
 	if _, ok := NormalizeBgMode("zoom"); ok {
 		t.Fatal("unknown mode should fail")
 	}
+	for _, legacy := range []string{"repeat-x", "repeat-y", "center"} {
+		if _, ok := NormalizeBgMode(legacy); ok {
+			t.Fatalf("legacy mode %s should fail", legacy)
+		}
+	}
 	for _, want := range []string{
-		BgModeCover, BgModeContain, BgModeRepeat, BgModeRepeatX, BgModeRepeatY, BgModeStretch, BgModeCenter,
+		BgModeCover, BgModeContain, BgModeRepeat, BgModeStretch,
 	} {
 		got, ok := NormalizeBgMode(" " + want + " ")
 		if !ok || got != want {