test: reproduce #1637 — browser pane reloads on tab switch

[github-actions]

What the bug is

When a user navigates away from a tab containing a browser pane and then switches back, the in-app browser reloads its page from scratch, losing all state (scroll position, form inputs, etc.).

What code is affected and why

The root cause is in usePersistentWebview.ts. The hook manages a module-level webviewRegistry (a Map<paneId, WebviewTag>) and an off-screen hiddenContainer. When BrowserPane unmounts (tab switch away), its useEffect cleanup appends the <webview> element to the hidden container:

// cleanup (line ~323)
getHiddenContainer().appendChild(wv);

When BrowserPane remounts (tab switch back), the effect "reclaims" the webview:

// effect (line ~136)
container.appendChild(webview); // "Reclaim from hidden container"

In Electron, appending a <webview> element to a different parent destroys and recreates its renderer process, which fully reloads the page. The code even acknowledges this implicitly — the handleDomReady handler re-registers a new webContentsId after "DOM reparenting" — but no attempt is made to prevent the reparenting in the first place.

What the test does

usePersistentWebview.test.ts contains:

1. 8 passing sanitizeUrl tests — baseline coverage for the URL-normalization helper (also exported so it can be tested directly).

2. 1 failing bug-reproduction test — simulates the three-step DOM lifecycle that causes the reload:

   • Step 1 (mount): webview → active-container
   • Step 2 (tab switch away / cleanup): webview → hidden-container ← reparent Bump react-dom from 18.3.1 to 19.2.0 #1
   • Step 3 (tab switch back / remount): webview → active-container ← reparent Bump lucide-react from 0.468.0 to 0.546.0 #2

   The test asserts parentHistory should equal ["active-container"] (i.e., no reparenting ever). It fails because parentHistory is ["active-container", "hidden-container", "active-container"], proving the reparenting — and therefore the reload — occurs.

The fix will need to keep the webview in a single parent and toggle CSS display/visibility instead of moving it between containers.

Closes #1637

[Kitenite]

Closing: stale bot-generated test reproduction stub with no follow-up activity.

[github-actions]

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