Send executive-meeting notifications via email + in-app alerts

Wired the Executive Meetings module to actually deliver notifications
when meeting/request/task events happen, instead of just storing
scheduled-notification rows.

Backend (artifacts/api-server):
- New helper `lib/executive-meeting-notify.ts`:
  - `recordExecutiveMeetingNotifications` inserts rows into both
    `executive_meeting_notifications` (the page's Notifications tab)
    and the global `notifications` table (the bell), inside the
    caller's transaction. Self-notifications are excluded; recipients
    are deduped.
  - `broadcastExecutiveMeetingNotifications` emits Socket.IO
    `notification_created` to each recipient's `user:${id}` room and
    one `executive_meeting_notifications_changed` global event. Called
    after the surrounding transaction commits.
  - `getUserIdsForRoleNames` resolves role holders via direct
    `user_roles` and indirect `group_roles` -> `user_groups`.
  - `sendExecutiveMeetingEmail` is a best-effort side-channel that
    logs an outbox entry when SMTP_HOST is unset (no nodemailer
    dependency added yet — see follow-up task).
  - `getUserDisplay` resolves bilingual display names with username
    fallback for use in notification titles/bodies.
- `routes/executive-meetings.ts` wired notifications into:
  - POST /executive-meetings (notify approvers — meeting_created)
  - POST /executive-meetings/requests and POST
    /executive-meetings/:id/requests (notify approvers + email outbox
    — request_submitted)
  - PATCH /executive-meetings/requests/:id (notify requester —
    request_approved/rejected/needs_edit; if approved with assignee,
    notify assignee — task_assigned)
  - POST /executive-meetings/tasks (notify assignee — task_assigned)
  - PATCH /executive-meetings/tasks/:id (reassign -> task_assigned;
    completion -> task_completed to original requester + previous
    assignee)

Frontend (artifacts/tx-os):
- `hooks/use-notifications-socket.ts` listens for
  `executive_meeting_notifications_changed` and invalidates the
  notifications/requests/tasks query keys so the page re-fetches in
  real time.
- `locales/en.json` + `locales/ar.json`: replaced placeholder intro
  with the real description and added type labels for the seven new
  notification types.

Verification:
- Restarted the API server (clean build).
- HTTP integration test: logged in as admin, created a meeting,
  submitted a request, approved the request — confirmed
  `executive_meeting_notifications` and `notifications` rows were
  inserted with correct counts (7 admins, actor excluded), the
  request_submitted email outbox log fired with bilingual subject/
  body and 6 deliverable email recipients, and self-notifications
  were correctly suppressed when actor == requester == reviewer.

No deviations from the original plan. Email delivery, per-user
notification preferences, and automated tests for the fan-out logic
are tracked as follow-ups.

Replit-Task-Id: accea784-663c-4b63-a492-8e20d648eb4c

artifacts/tx-os/src/hooks/use-notifications-socket.ts

@@ -86,6 +86,18 @@ export function useNotificationsSocket() {
       },
     );
 
+    socket.on("executive_meeting_notifications_changed", () => {
+      queryClient.invalidateQueries({
+        queryKey: ["/api/executive-meetings/notifications"],
+      });
+      queryClient.invalidateQueries({
+        queryKey: ["/api/executive-meetings/requests"],
+      });
+      queryClient.invalidateQueries({
+        queryKey: ["/api/executive-meetings/tasks"],
+      });
+    });
+
     socket.on(
       "role_permissions_changed",
       (payload?: { roleId?: number }) => {