complete performance and reliability follow-ups

packages/dev-server/src/assets.ts

@@ -19,6 +19,7 @@ import {
 } from "@wrnexus/csr";
 import {
   renderStyles,
+  renderActiveThemeCss,
   renderThemeCss,
   renderThemeRuntime,
   type ResolvedTheme,
@@ -122,6 +123,18 @@ export function createDevAssetServer(
           ? cssResponse(renderThemeCss(theme))
           : new Response("Not Found", { status: 404 });
       }
+      const activeThemeMatch = /^\/__wrnexus\/theme\/([^/]+)\/([^/]+)\.css$/.exec(pathname);
+      if (activeThemeMatch && theme) {
+        try {
+          const themeName = decodeURIComponent(activeThemeMatch[1]!);
+          const accentPart = decodeURIComponent(activeThemeMatch[2]!);
+          return cssResponse(
+            renderActiveThemeCss(theme, themeName, accentPart === "_" ? undefined : accentPart),
+          );
+        } catch {
+          return new Response("Not Found", { status: 404 });
+        }
+      }
       if (pathname === "/__wrnexus/theme.js") {
         return theme
           ? jsResponse(renderThemeRuntime(theme))