A test pins /boards as an admin's: a guest and a non-admin get not found on every board page and edit, and nothing changes #6855

src/web/pages/boards-view.ts says "anyone but a person who is an admin gets the not-found page" and boards-edit.ts takes eight operations; no test imports either.

Done:

• [ ] test/boards-doors.test.ts: as a guest and as a signed-in non-admin, GET /boards, /boards/:slug and /boards/:slug/live answer not found.
• [ ] As those two, POST /boards/new, /boards/pin and /boards/:slug/:op for rename, settings, add, edit, remove, move, duplicate and delete each refuse, and the board reads exactly as before.
• [ ] An admin's rename and delete work, each with a redirect and flash.

Files: a test only.

Before pushing: bun x tsc --noEmit and the tests you add or touch; bun scripts/design-lint.ts if src/web/ changes. Small and single-purpose; tests never read the wall clock — pass now in.