The living QA doc's copy-pasteable coverage-recon greps pointed at
client/App.jsx, Sidebar.jsx, <Page>.jsx and the B-UI primitive census
listed button.jsx/input.jsx/etc — all now .tsx, so the commands errored
('No such file'). Retargeted to .tsx (+ useAutoSave.test.ts) and noted
that recon greps target .tsx and 'npm run typecheck' is now a guard.
Behavior-only migration: client 42/42 + e2e probe 17/17 stay green.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>