fix(studio): build:dev mode, lint exclude .hyperframes, iframe ref guard

CLAUDE.md

@@ -22,6 +22,20 @@ bun run test    # Run tests
 
 **This repo uses bun**, not pnpm. Do NOT run `pnpm install` — it creates a `pnpm-lock.yaml` that should not exist. Workspace linking relies on bun's resolution from `"workspaces"` in root `package.json`.
 
+### Studio Build
+
+Always use the dev build locally — source maps, no minification, React dev-mode warnings:
+
+```bash
+bun run --cwd packages/studio build:dev
+```
+
+The production build (`build` without `:dev`) is only run by GitHub Actions for publish. After building, copy to CLI:
+
+```bash
+rm -rf packages/cli/dist/studio && cp -r packages/studio/dist packages/cli/dist/studio
+```
+
 ### Linting & Formatting
 
 This project uses **oxlint** and **oxfmt** (not biome, not eslint, not prettier).

packages/core/src/studio-api/routes/lint.ts

@@ -9,7 +9,9 @@ export function registerLintRoutes(api: Hono, adapter: StudioApiAdapter): void {
     const project = await adapter.resolveProject(c.req.param("id"));
     if (!project) return c.json({ error: "not found" }, 404);
     try {
-      const htmlFiles = walkDir(project.dir).filter((f) => f.endsWith(".html"));
+      const htmlFiles = walkDir(project.dir).filter(
+        (f) => f.endsWith(".html") && !f.startsWith(".hyperframes/") && !f.startsWith("node_modules/"),
+      );
       const allFindings: Array<{
         severity: string;
         message: string;

packages/studio/src/App.tsx

@@ -256,6 +256,7 @@ export function StudioApp() {
   const { syncPreviewTimelineHotkey, syncPreviewHistoryHotkey } = appHotkeys;
   const handlePreviewIframeRef = useCallback(
     (iframe: HTMLIFrameElement | null) => {
+      if (previewIframeRef.current === iframe) return;
       previewIframeRef.current = iframe;
       setPreviewIframe(iframe);
       syncPreviewTimelineHotkey(iframe);