fix(W3): 预览资产代理前缀拼 request.getContextPath(/yschcms 下 CSS 404 裸 HTML),T-W3-01..04 全绿+全量 264/264

src/test/java/com/yunhai/cms/theme/PreviewApiIT.java

@@ -137,6 +137,17 @@ class PreviewApiIT extends CmsIntegrationTestBase {
         assertThat(body(result)).contains("/api/theme/t-demo-red/asset/css/main.css");
     }
 
+    @Test
+    @DisplayName("T-W3-04: 端到端回归：contextPath=/yschcms 时预览资产 href 带上下文前缀")
+    void previewAssetHrefCarriesContextPathEndToEnd() throws Exception {
+        MvcResult result = standalone.perform(get("/yschcms/api/theme/preview")
+                        .contextPath("/yschcms")
+                        .param("siteCode", "demo").param("theme", "t-demo-red"))
+                .andExpect(status().isOk()).andReturn();
+        assertThat(body(result))
+                .contains("href=\"/yschcms/api/theme/t-demo-red/asset/css/main.css\"");
+    }
+
     @Test
     @DisplayName("T26: 预览响应 no-store（不进缓存/CDN）")
     void previewNoStore() throws Exception {