Agentic UI: Always clear the preview cache when reloading

[bcotrim]

Related issues

• Follow-up to Agentic UI: Recover the site preview from cached cross-site redirects #4505 / STU-2217, implementing @sejas's review suggestion.

How AI was used in this PR

Claude Code made the change. It's a net deletion of the surface added in #4505.

Proposed Changes

#4505 added a separate "Hard refresh" option so users could shake loose a stale cached redirect. @sejas pointed out that the regular refresh button could just do this in all cases — then there's nothing extra to discover, and it also fixes the everyday annoyance of edited CSS/JS being served stale during development.

Reloading the preview now always drops the HTTP cache. Cost is limited to an explicit user action, and previews are local, so a refresh is cheap. Cookies live in a separate store, so preview logins are unaffected.

One thing had to come along: clearing the cache isn't enough on its own, because a cached redirect moves the webview's current entry onto the other site and reload() would reload that. Reload now re-navigates to the site's own URL when it detects it's sitting off-origin, and reloads normally otherwise.

The dedicated menu item is gone, ⌘⇧R stays as an alias for reload so the browser habit isn't a dead key, and the automatic recovery from #4505 is unchanged.

Trade-off: you can no longer reload the preview with a warm cache, so you can't observe how your site behaves for a returning visitor.

Testing Instructions

1. With a site running, edit a file its theme loads directly (e.g. add body { background: red } to the active theme's style.css).
2. Press ⟳ in the preview — the change shows without any manual cache clear. Confirm ⌘⇧R does the same.
3. Redirect recovery still works. Create a second site, give the first a wp-content/mu-plugins/redirect.php that 301s its front end to the second's port:

   <?php
   add_action( 'template_redirect', function () {
       wp_redirect( 'http://localhost:<other-port>/', 301 );
       exit;
   } );

   Open its preview (shows the other site), delete the mu-plugin, confirm curl -sI returns 200 with no Location, then press ⟳ — it returns to the right site.
4. Switching away and back should still self-heal without pressing anything.
5. Confirm wp-admin still auto-logs in after a reload — the cache clear must not drop cookies.

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[wpmobilebot]

📊 Performance Test Results

Comparing 9abcb20 vs trunk

app-size

Metric	trunk	9abcb20	Diff	Change
App Size (Mac)	1406.62 MB	1406.62 MB	0.00 MB	⚪ 0.0%

site-editor

Metric	trunk	9abcb20	Diff	Change
load	1060 ms	1030 ms	30 ms	⚪ 0.0%

site-startup

Metric	trunk	9abcb20	Diff	Change
siteCreation	7528 ms	7516 ms	12 ms	⚪ 0.0%
siteStartup	2870 ms	2868 ms	2 ms	⚪ 0.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[sejas]

Works as expected thanks! Now we'll use hard refresh always minimizing any other issue.

hard-refresh-fixes-301.mp4