v4.0.2

fix(gitignore): stop excluding app_patches/app from the repository

.gitignore carried unanchored `app/`, `build/` and `dist/` rules. Git
matches those at any depth, so alongside the intended top-level artefact
directories they also excluded:

    app_patches/app/app.bundle.js
    app_patches/app/js/debug-reporter.js
    app_patches/app/js/directives/welcome-page.js
    app_patches/app/js/lib/api/screen-capture.js
    app_patches/node_modules/{jsbi,long}/dist/
    app_patches/node_modules/nsfw/build/

ensure-extracted-app.sh applies app_patches with `cp -r app_patches/. app/`,
so any build from a clean checkout silently skipped every one of them. CI
builds only ever saw app_patches/my_modules and app_patches/node_modules,
which means the published packages shipped upstream's Windows
screen-capture.js rather than the XDG portal implementation, and the
unpatched app.bundle.js.

Anchor the three rules to the repository root. The top-level app/, build/
and dist/ payload directories stay ignored exactly as before; only the
nested paths under app_patches/ become visible. Verified both halves of
that with git check-ignore.

Co-Authored-By: Claude <noreply@anthropic.com>