Add restaurant/café mode: floor, open tabs, and kitchen display (Phase 1)

Gated by a per-location service_style (retail | restaurant). Restaurant mode adds:
- Floor screen with tables (areas, seats, status) — tap a free table to open a
  dine-in tab; takeaway/counter orders open from the same screen.
- Open tickets (tabs): a sale stays pending while items are added; lines persist
  as you go (posTicket Alpine component posts each change to the server).
- Send-to-kitchen fires un-sent lines; a polling Kitchen Display (KDS) shows
  active tickets and bumps items queued → preparing → ready → served.
- Settlement reuses the existing cash / Ladill Pay flow; paying closes the tab
  and frees the table (PosSaleService::closeTicket, wired into both pay paths).
- Settings gains the mode toggle and a tables manager.

Schema is additive (new pos_tables; service_style on locations; order/kitchen
columns on sales + lines). Retail flow is untouched. Sidebar surfaces Floor +
Kitchen only in restaurant mode. New PosRestaurantTest covers the dine-in
lifecycle end to end; suite green (10 passed).

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

app/Models/PosTable.php

@@ -0,0 +1,56 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+class PosTable extends Model
+{
+    public const STATUS_FREE = 'free';
+
+    public const STATUS_OCCUPIED = 'occupied';
+
+    public const STATUS_BILL_REQUESTED = 'bill_requested';
+
+    protected $fillable = [
+        'owner_ref',
+        'location_id',
+        'area',
+        'label',
+        'seats',
+        'status',
+        'current_sale_id',
+        'position',
+    ];
+
+    protected function casts(): array
+    {
+        return [
+            'seats' => 'integer',
+            'current_sale_id' => 'integer',
+            'position' => 'integer',
+        ];
+    }
+
+    public function location(): BelongsTo
+    {
+        return $this->belongsTo(PosLocation::class, 'location_id');
+    }
+
+    public function currentSale(): BelongsTo
+    {
+        return $this->belongsTo(PosSale::class, 'current_sale_id');
+    }
+
+    public function isFree(): bool
+    {
+        return $this->status === self::STATUS_FREE;
+    }
+
+    public function scopeOwned(Builder $query, string $ownerRef): Builder
+    {
+        return $query->where('owner_ref', $ownerRef);
+    }
+}