[CMS-VISUAL] E 激进清场: 下架 10 套伪主题（tag themes-before-cleanup-2026-09 + docs/主题备份/ 双备份）→ 保留 default/scholar-blue/campus-glow 三套；色皮档并入 default.colorScheme、克隆档并入 scholar-blue.colorScheme（ThemeParam.presets + ThemeVarsCss 变量组注入）；别名表 R-46 映射（渲染端不断渲染 + 保存归一化 + 站点级 theme_params.colorScheme）

src/main/java/com/yunhai/cms/theme/ThemeRegistry.java

@@ -44,6 +44,44 @@ public class ThemeRegistry {
     public static final String SOURCE_BUILTIN = "builtin";
     public static final String SOURCE_EXTERNAL = "external";
 
+    /**
+     * docs/20 E（激进清场）下架主题别名表：原主题名 → [保留主题, colorScheme 预设值]。
+     * 存量站点 theme 仍写下架名时按本表解析（R-46：门户不断渲染，不 404）；
+     * 站点下次保存时由 SiteService 归一化为保留主题 + config.theme_params.colorScheme。
+     */
+    private static final java.util.Map<String, String[]> DEPRECATED_ALIASES = java.util.Collections.unmodifiableMap(
+            new java.util.LinkedHashMap<String, String[]>() {{
+                // 色皮档 4 套 → default 预设
+                put("blue-white", new String[] {DEFAULT_THEME, "blue-white"});
+                put("classic-red", new String[] {DEFAULT_THEME, "classic-red"});
+                put("fresh-mint", new String[] {DEFAULT_THEME, "fresh-mint"});
+                put("warm-kinder", new String[] {DEFAULT_THEME, "warm-kinder"});
+                // 骨架克隆档 6 套 → scholar-blue 预设
+                put("academic-navy", new String[] {"scholar-blue", "navy"});
+                put("campus-azure", new String[] {"scholar-blue", "azure"});
+                put("poly-blue", new String[] {"scholar-blue", "poly"});
+                put("agri-forest", new String[] {"scholar-blue", "agri"});
+                put("jade-normal", new String[] {"scholar-blue", "jade"});
+                put("mint-breeze", new String[] {"scholar-blue", "mint"});
+            }});
+
+    /** 下架别名解析结果：target=保留主题名；colorScheme=对应预设值（可能为 null） */
+    public static final class AliasInfo {
+        public final String target;
+        public final String colorScheme;
+
+        AliasInfo(String target, String colorScheme) {
+            this.target = target;
+            this.colorScheme = colorScheme;
+        }
+    }
+
+    /** 下架别名解析：非别名返回 null */
+    public static AliasInfo aliasOf(String name) {
+        String[] mapped = name == null ? null : DEPRECATED_ALIASES.get(name);
+        return mapped == null ? null : new AliasInfo(mapped[0], mapped[1]);
+    }
+
     /** 包名与目录名约束（方案 §4.1） */
     private static final Pattern NAME_PATTERN = Pattern.compile("^[a-z][a-z0-9-]{1,30}[a-z0-9]$");