Untrack the emitted vite config, and select biome's files by extension

vite.config.js and vite.config.d.ts are tsc output of vite.config.ts, emitted
next to the source when the composite tsconfig.node.json is built. Nothing
reads them — and vite picks a vite.config.js ahead of the .ts, so the committed
copy was quietly shadowing the real config. Gitignore both.

The biome hook selected by the frontend/ prefix and passed the staged paths on,
but `bun run lint` runs in frontend/, so biome saw frontend/frontend/… and
reported an internal io error for every staged file. The script already lints
the whole tree, so stop passing filenames and let the pattern — now the
extensions biome parses — decide only whether the hook runs.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01CL9zvnnvcp1mvA8o7impxk

.gitignore

@@ -20,5 +20,11 @@ __pycache__/
 /frontend/screenshots/
 *.tsbuildinfo
 
+# Emitted next to the source when the composite tsconfig.node.json is built
+# (`tsc -b`). Nothing consumes them, and vite picks a vite.config.js ahead of
+# the .ts source — so a committed copy would silently shadow the real config.
+/frontend/vite.config.js
+/frontend/vite.config.d.ts
+
 # Output of `make docs` (the zensical build of docs/).
 /site/