refactor(logs): share the update-marker row between the three log views #104

Follow-up to #38.

Problem #

The update-marker row is rendered three times, in DeliveryLog, LogsBrowser and AdminLogsBrowser, each with its own hardcoded colSpan (4, 5 and 7). The predatesNote and markerCell styles are copied between DeliveryLog.css.ts and LogsBrowser.css.ts. A change to the marker has to be made three times, and a column added to one table leaves its marker row short.

Evidence #

• app/islands/DeliveryLog.css.ts:103 and app/islands/LogsBrowser.css.ts:104-110: the same predatesNote / markerCell styles.
• The marker-row JSX in DeliveryLog, LogsBrowser and AdminLogsBrowser, with colSpan 4, 5 and 7.

Expected #

One component (with one style) renders the marker row and takes the column count from its table.

Acceptance criteria #

• The marker row and its styles exist once.
• Each log view passes its column count instead of hardcoding it.
• Existing marker tests pass for all three views.