fix: tell receivers when an order is no longer available + fix disabled apps disappearing from admin

## Task #80 — Tell receivers when an order is no longer available to claim

### Problem
When a receiver tried to act on an order that had already been cancelled, completed,
or claimed by someone else, the UI showed a generic "Could not complete the action"
toast. The stale card also stayed in the list, requiring a manual refresh.

### Changes

**artifacts/api-server/src/routes/service-orders.ts**
- PATCH /orders/:id/confirm-receipt: after a failed atomic claim, query the current
  order status; return 409 `order_unavailable` if it's cancelled/completed (vs the
  existing 409 `already_claimed` for when it was grabbed by someone else first)
- PATCH /orders/:id/status (preparing/completed branch): terminal-state check runs
  BEFORE permission gating — returns 409 `order_unavailable` when order is already
  cancelled/completed instead of ever hitting 403 Forbidden
- PATCH /orders/:id/status (cancel branch): same — terminal-state check moved to
  the top of the branch so non-admin receivers trying to cancel an already-terminal
  order get 409 `order_unavailable` (not 403 Forbidden which would never let the UI
  remove the stale card)

**artifacts/tx-os/src/pages/orders-incoming.tsx**
- handleConfirmReceipt onError: distinguish 409 `order_unavailable` from
  `already_claimed`, show specific toast, remove stale card via invalidate()
- handleSetStatus onError: same pattern — specific toast + invalidate() on
  `order_unavailable`
- handleCancel onError: same pattern

**artifacts/tx-os/src/locales/en.json + ar.json**
- Added `incomingOrders.orderUnavailable` ("This order is no longer available" /
  "هذا الطلب لم يعد متاحاً")

## Bonus fix — Disabled app disappears from admin panel (user-reported)

### Problem
When an admin disabled an app via the toggle, the app disappeared from the admin
panel too (isActive filter applied to everyone), making it impossible to re-enable
without direct DB access.

### Changes

**artifacts/api-server/src/routes/apps.ts**
- getVisibleAppsForUser: admins now receive ALL apps including inactive ones via
  conditional $dynamic() Drizzle query; non-admins still only see active apps

**artifacts/tx-os/src/pages/home.tsx**
- Filter orderedApps to only active apps before rendering so inactive apps don't
  appear on the home screen even for admins

**artifacts/tx-os/src/pages/admin.tsx**
- Inactive app cards show reduced opacity + a "Disabled/معطّل" badge

**artifacts/tx-os/src/locales/en.json + ar.json**
- Added `admin.appDisabled` ("Disabled" / "معطّل")

artifacts/tx-os/src/pages/home.tsx

@@ -299,14 +299,15 @@ export default function HomePage() {
 
   useEffect(() => {
     if (!apps) return;
+    const activeApps = apps.filter((a) => a.isActive);
     setOrderedApps((prev) => {
-      if (!prev) return apps;
-      const byId = new Map(apps.map((a) => [a.id, a]));
+      if (!prev) return activeApps;
+      const byId = new Map(activeApps.map((a) => [a.id, a]));
       const kept = prev
         .map((a) => byId.get(a.id))
         .filter((a): a is App => a !== undefined);
       const keptIds = new Set(kept.map((a) => a.id));
-      const added = apps.filter((a) => !keptIds.has(a.id));
+      const added = activeApps.filter((a) => !keptIds.has(a.id));
       return [...kept, ...added];
     });
   }, [apps]);