fix(app): reread files when opening a preview - #51036

browser.preview and file links in the timeline showed old file content. This was true even when you closed and opened the tab again.

Cause

• useFile().load(path) returns early when the file is already loaded.
• V2 only watches .git/HEAD and .hg/branch, so the app never gets a filesystem.changed event for workspace files. The stored copy stays until the cache evicts it.
• Closing a tab does not clear the stored copy.

flowchart LR
  A[browser.preview / file link] --> B["file.load(path)"]
  B -->|already loaded| C[show stored copy ❌]
  B -->|"{ force: true }"| D["GET /api/fs/read"] --> E[show current file ✅]

Fix

• openTab in packages/app/src/session/files/open-artifact.tsx now calls file.load(path, { force: true }).
• While the file loads, the tab keeps the old content on screen, so it does not flash.

void file.load(path, { force: true }).then(() => {
  if (file.get(path)?.loaded) showTab(file.tab(path))
})

• Adds the regression test e2e/regression/artifact-reopen.spec.ts: open a file, change it, close the tab, open it again, and expect the new content.

Before	After

The file on disk says second draft in both images.