#262: remove Requests / Approvals / Tasks tabs from Executive Meetings

Full-stack removal of the three retired sections — UI, locales, realtime
invalidations, backend routes, role lists, capability flags, schema
tables, notify lib, and tests.

Backend (artifacts/api-server)
- routes/executive-meetings.ts: deleted /requests* + /tasks* handler
  block, REQUEST_ROLES / TASK_VIEW_ROLES / TASK_BROAD_VIEW_ROLES,
  canSubmitRequest / canViewTasks / canViewAllTasks from /me, retired
  table imports, and dead schemas (detailsByType, requestPayloadSchemas,
  request*Schema, taskCreateSchema, taskPatchSchema, dueAtSchema,
  dateOnly, timeHm). canApprove kept (still used by FontSettings).
- lib/executive-meeting-notify.ts: EXECUTIVE_MEETING_NOTIFICATION_TYPES
  collapsed to ['meeting_created'].

Frontend (artifacts/tx-os)
- pages/executive-meetings.tsx: deleted RequestsSection /
  ApprovalsSection / TasksSection / RequestListRow, pruned SECTIONS,
  MeCapabilities / MeRoles types, isSectionVisible cases, icon imports.
- hooks/use-notifications-socket.ts: dropped the two retired query
  invalidations.
- locales/{ar,en}.json: removed nav.{requests,approvals,tasks},
  executiveMeetings.{requests,approvals,tasks} subtrees, and the 6
  retired notification.type entries.

Schema + DB
- lib/db/src/schema/executive-meetings.ts: tables + relations + types
  for requests/tasks removed.
- artifacts/api-server/scripts/cleanup-em-requests-tasks.sql:
  idempotent BEGIN/COMMIT — deletes orphan prefs / notifications /
  audit rows, then DROP TABLE … CASCADE for both retired tables.
  Applied to dev DB and `db push` re-synced.

Tests
- executive-meetings.test.mjs: deleted 9 retired blocks + 2 covered
  prefs duplicates, rewrote /me capability test to assert flags absent,
  rewrote DELETE-wipe test to use meeting_created via POST
  /api/executive-meetings, removed /requests + /tasks router.param
  entries.
- executive-meetings-notifications.test.mjs: deleted 7 blocks
  (request_*, task_*, cross-event-mute), updated before/after
  cleanup to skip dropped tables, kept setPref/clearPref helpers
  (still used by surviving meeting_created opt-out tests).

Drift / pre-existing
- 3 test failures observed under the parallel `node --test` workflow
  (meeting_created fan-out count, pref opt-out daily-number conflict,
  service-orders JSON-vs-HTML) are pre-existing parallel-file
  pollution between executive-meetings.test.mjs and
  executive-meetings-notifications.test.mjs. Verified by running
  `node --test --test-concurrency=1 'tests/**/*.test.mjs'` →
  226/226 pass. Out of scope for #262.
- Pre-existing tsc warnings at routes/executive-meetings.ts L509/625
  (boolean/number on isHighlighted) and L1594 (font-settings scope
  query) untouched.

artifacts/api-server/scripts/cleanup-em-requests-tasks.sql

@@ -0,0 +1,50 @@
+-- #262: Executive Meetings Requests/Approvals/Tasks removal cleanup.
+--
+-- Drops the two retired tables and scrubs orphaned rows from the
+-- surviving Executive Meetings tables that referenced them by string.
+-- Idempotent: safe to re-run. Wraps everything in a single transaction
+-- so a partial failure leaves the DB unchanged.
+--
+-- Run order:
+--   1) Apply this script to dev / prod databases.
+--   2) Run `pnpm --filter @workspace/db push` to confirm the Drizzle
+--      schema and the database are in sync (should be a no-op).
+--
+-- Run command (dev):
+--   psql "$DATABASE_URL" -f artifacts/api-server/scripts/cleanup-em-requests-tasks.sql
+
+BEGIN;
+
+-- 1. Notification preferences rows for retired event types.
+DELETE FROM executive_meeting_notification_prefs
+WHERE notification_type IN (
+  'request_submitted',
+  'request_approved',
+  'request_rejected',
+  'request_needs_edit',
+  'task_assigned',
+  'task_completed'
+);
+
+-- 2. Notifications rows for retired event types (executive-meeting domain only).
+DELETE FROM executive_meeting_notifications
+WHERE notification_type IN (
+  'request_submitted',
+  'request_approved',
+  'request_rejected',
+  'request_needs_edit',
+  'task_assigned',
+  'task_completed'
+);
+
+-- 3. Audit logs that targeted request/task entities.
+DELETE FROM executive_meeting_audit_logs
+WHERE entity_type IN ('request', 'task');
+
+-- 4. Drop the retired tables themselves. CASCADE removes any FK indices
+--    that referenced them; nothing in the surviving schema depends on
+--    these two tables.
+DROP TABLE IF EXISTS executive_meeting_tasks CASCADE;
+DROP TABLE IF EXISTS executive_meeting_requests CASCADE;
+
+COMMIT;