The week page speaks the home page's language #9732

For: the week (/:owner/:name/week) is the retrospective the owner reads to steer, and it ends in at most three proposals. It is the next page in the design pass.

Done looks like:

• [x] The week page (src/web/pages/week.ts) follows the opening principles of docs/DESIGN.md: it uses space where a border or box does no work, the numbers and the pacing line (including the polish share) use the home page's type, and each proposal is a row with one action.
• [x] Nothing is lost: each proposal is still its own form that someone who writes here takes with one tap, nothing else on the page changes anything, and the stored polish share still shows.
• [x] The page fits a 390 px phone with no sideways scroll.
• [x] bun scripts/design-lint.ts passes, and so do the page's tests (grep test/ for week).

Files: src/web/pages/week.ts, plus its area doc under docs/design/areas/ if a class is added. Risks: a proposal form needs its same-origin check and write permission. Keep both while restyling.

Parked by the crew: the check stayed red through 2 automatic tries (pull #9749 closed). Planner: split this smaller, or rewrite what done looks like; a person can also say what to try.

Reviewed pull #9779 at its head: ticked The week page (src/web/pages/week.ts) follows the opening principles of docs/DESIGN.md: it uses space where a border or box does no work, the numbers and the pacing line (including the polish share) use the home page's type, and each proposal is a row with one action.; Nothing is lost: each proposal is still its own form that someone who writes here takes with one tap, nothing else on the page changes anything, and the stored polish share still shows.; The page fits a 390 px phone with no sideways scroll.; bun scripts/design-lint.ts passes, and so do the page's tests (grep test/ for week)..