chore(desktop): keep the lint run away from build output - #240

Outcome

bun run lint (ultracite check) no longer hangs when a build output directory exists. The dev
watcher rebuilds apps/desktop/dist/ on every source edit, so the failure used to appear at random
during ordinary development: the run burned a core for minutes and then reported an error over the
bundled renderer's embedded xterm banner.

Cause, verified on the live checkout: ultracite runs oxlint . and oxfmt --check .. oxlint
honours this repo's ignorePatterns (dist/**, build/**, …) and finished in seconds, while
apps/desktop/oxfmt.config.ts ignored only src-tauri/gen, src-host, asset JSON and artifacts,
so the formatter walked the ~48 MB bundled renderer — including a 5 MB vendor bundle — on every run.

oxfmt.config.ts now ignores **/dist/** and **/build/**, with the reason recorded beside them.

Change record

• Change: docs/sdlc/changes/2026-09-16-lint-ignore-build-output/intent.md

The linked change directory owns scope, authorization, acceptance, evidence, and residual risk.

Review and release

• Acceptance evidence covers the current diff: with dist/ present (48 MB) bun run lint
  finished in 8.8 s and bun run build:renderer completed (All matched files use the correct format. + ✓ built in 24.04s) where the same commands previously never returned; the
  maintained file verdict is unchanged.
• Required checks passed on this base: bun run lint, bun run build:renderer,
  bun script/verify/sdlc.ts --worktree, bun script/verify/docs.ts.
• Merge authorization: pending (this PR was requested; merge is not authorized)
• Release authorization: not requested