feat(kds): filter the kitchen display by station (kitchen / bar)

Complements the separate kitchen/bar printers with an on-screen split. The live
order DTO now carries each item's prep station (MenuItem → Category →
KitchenStation), and the KDS shows station tabs (All / Kitchen / Bar / …) that
appear only once ≥2 stations are in play. Selecting a station shows just the
tickets — and just the items within each ticket — for that station, so bar staff
see drinks and kitchen staff see food. Single-station cafés see the board
unchanged. fa/en/ar strings added.

Note: order status is still per-order (one advance button); the split is for
viewing/printing, not per-item status.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/Meezi.API/Models/Orders/OrderDtos.cs

@@ -10,7 +10,11 @@ public record OrderItemDto(
     decimal UnitPrice,
     string? Notes,
     bool IsVoided = false,
-    DateTime? VoidedAt = null);
+    DateTime? VoidedAt = null,
+    // Prep station the item routes to (Kitchen/Bar). Populated on the live/KDS
+    // path only; null elsewhere (= the branch kitchen / no station).
+    string? StationId = null,
+    string? StationName = null);
 
 public record TransferTableRequest(string TargetTableId);