Fix labels sitting too close to their inputs. In Tailwind v4, `space-y-*` sets margin-bottom on the label, and a plain `<label>` is inline — inline elements ignore top and bottom margins, so the spacing did nothing. `ui/label.tsx` is now `block`, which takes the gap from 1.8px to the 8px it was meant to be, in every form.

- Show the period title in the /manage list. New Title column, and the whole row is now one `PeriodTableRow` component so the period body is read once per row instead of twice — the title and the ballot label both come from it, and the list query doesn't include it.

- The voting window column now shows dates only, with the full UTC times on hover. This needed a new `formatDateRangeUTC`: the existing `formatDateRange` uses the viewer's timezone, and the manage panel works in UTC, so it could show a different day than the tooltip below it.

- Sample data: election ballots read Support / Veto / Abstain, matching what the manage UI writes.

- Mirror the GT_OA rule from `ensureValidOptions` in the manage panel, so an operator cannot build an option list the contract will reject.

- There's a fixed row with "Abstain" option, locked and without move/remove controls. Both editors hold only the custom options and append Abstain at call time.

- Frontend is even stricter than the contract: enforces `MIN_CUSTOM_OPTIONS=2` (at least two non-abstain options) and rejects an operator-typed Abstain in any casing.

- Create a new utils file for topic options to centralize validation for add/edit topic options. Also adds the missing duplicate-option check to AddTopic.

chore: consolidate over-split files