#486: Executive Meetings row click → quick-actions popover

Clicking any meeting row on the Executive Meetings schedule (gated only
on canMutate, not editMode) opens a small popover with Move up / Move
down / Postpone. Move up/down swap only the (startTime, endTime) tuple
between the clicked meeting and its chronological neighbour on the same
date — the Time column stays visually anchored to its row position.

Backend
- POST /executive-meetings/swap-times: transactional swap with FOR
  UPDATE row locking, optimistic-lock conflict shape (stale_meeting +
  conflict payload), date/time-window guards, audit logging, and
  renumberDayByStartTime + day-changed broadcast.
- Zod schema in lib/api-zod/src/manual.ts.

Frontend
- Shared lib/api-json.ts JSON helper.
- ScheduleSection.swapTimes does an optimistic (startTime, endTime)
  swap against the day query cache and rolls back on failure (mirrors
  the existing inline-edit UX).
- Edge enablement (canQuickMoveUp/Down) now derived from the full
  orderedMeetings index, not the search-filtered displayedMeetings, so
  "Move up/down" disabled state always matches the true day boundary
  (and never silently swaps with a hidden filtered neighbour).
- MeetingRow uses Popover/PopoverAnchor with skip rules: ARIA roles
  (button/checkbox/switch/combobox/dialog) and em-time-* / em-edit-* /
  em-row-grip / em-row-actions data-testid prefixes do NOT open the
  popover.
- PostponeDialog reused from upcoming-meeting-alert.tsx.

Tests
- Backend swap-times: happy path, stale_meeting (409), different_dates
  (400), no_time_window (400), unauth (401), viewer-no-mutate (403),
  malformed-timestamp (400) — all 7 pass.
- Hardened expectedUpdatedAt zod schema to z.string().datetime() so
  malformed tokens fail at validation with a controlled 400 instead of
  bubbling up as a 500.
- E2E: Move up swap, edge-disable states (solo / first / middle /
  last), Postpone 5-min chip end-to-end, click-exclusion on grip /
  time cell / row-actions — all 4 pass. Each test uses its own future
  date to avoid cross-test pollution.

Code review approved on second pass. Pre-existing failures in other
suites (executive-meetings reorder, font-settings, notes-share,
service-orders) are unrelated to this task and predate it.

Follow-ups proposed: #487 (keyboard a11y on the popover), #488 (edit-
mode test gaps).

artifacts/tx-os/src/pages/executive-meetings.tsx

@@ -2931,8 +2931,22 @@ function ScheduleSection({
                     bulkSelected={selectedMeetingIds.has(m.id)}
                     onBulkSelectChange={(v) => toggleMeetingSelected(m.id, v)}
                     quickActionsCanMutate={canMutate}
-                    canQuickMoveUp={idx > 0}
-                    canQuickMoveDown={idx < displayedMeetings.length - 1}
+                    // Edge enablement is computed against the FULL day order,
+                    // not the (possibly search-filtered) `displayedMeetings`.
+                    // quickMoveUp/Down resolve neighbours from
+                    // `orderedMeetings`, so deriving disabled state from the
+                    // filtered index would let a user click "Move up" on what
+                    // looks like the first visible row but is actually mid-day,
+                    // and silently swap with a hidden neighbour.
+                    canQuickMoveUp={
+                      orderedMeetings.findIndex((om) => om.id === m.id) > 0
+                    }
+                    canQuickMoveDown={(() => {
+                      const oIdx = orderedMeetings.findIndex(
+                        (om) => om.id === m.id,
+                      );
+                      return oIdx >= 0 && oIdx < orderedMeetings.length - 1;
+                    })()}
                     onQuickMoveUp={() => quickMoveUp(m.id)}
                     onQuickMoveDown={() => quickMoveDown(m.id)}
                     onQuickPostpone={() => setPostponeMeetingId(m.id)}