Restaurant mode Phase 3: table-QR self-ordering into the kitchen

The "links" slice — a guest scans a table's QR, browses the menu (with
modifiers), and submits an order that lands on that table's open tab and fires
straight to the Kitchen Display.

- Public, auth-free flow scoped by an unguessable table short_code:
  GET /t/{code} (menu + client cart), POST /t/{code}/order (throttled),
  GET /t/{code}/done. Orders open/append the table's dine-in tab, add lines as
  source=guest, and send to the kitchen.
- Staff print a per-table QR (Settings → table → QR; renders client-side to the
  public menu URL). short_code is generated lazily.
- Guest lines are badged on the ticket and the KDS so staff can tell them apart;
  staff still settle the tab as usual (cash / Ladill Pay).
- Extracted PosSaleService::buildProductLine as the single product+modifier
  price resolver, now shared by staff and guest ordering (client prices never
  trusted).

Schema additive: pos_tables.short_code, pos_sale_lines.source. New
PosRestaurantTest covers the guest order firing to the kitchen; suite green (12).

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

app/Services/Pos/PosSaleService.php

@@ -2,6 +2,7 @@
 
 namespace App\Services\Pos;
 
+use App\Models\PosProduct;
 use App\Models\PosSale;
 use App\Models\PosSaleLine;
 use App\Models\PosSaleLineModifier;
@@ -114,7 +115,39 @@ class PosSaleService
     }
 
     /**
-     * @param  array{product_id?: ?int, station_id?: ?int, course?: ?string, name: string, unit_price_minor: int, quantity?: int, notes?: ?string, modifiers?: list<array{modifier_id?: ?int, name: string, price_delta_minor?: int}>}  $line
+     * Resolve a catalog product (owner-scoped) + chosen modifiers into an addLine
+     * payload. Effective price = base + modifier deltas; null if product unknown.
+     *
+     * @param  list<int|string>  $modifierIds
+     * @return array<string,mixed>|null
+     */
+    public function buildProductLine(string $owner, int $productId, array $modifierIds = [], int $quantity = 1, ?string $notes = null, ?string $course = null, string $source = 'staff'): ?array
+    {
+        $product = PosProduct::owned($owner)->with('modifierGroups.modifiers')->find($productId);
+        if (! $product) {
+            return null;
+        }
+
+        $allowed = $product->modifierGroups->flatMap->modifiers->keyBy('id');
+        $chosen = collect($modifierIds)->map(fn ($id) => $allowed->get((int) $id))->filter()->values();
+
+        return [
+            'product_id' => $product->id,
+            'name' => $product->name,
+            'station_id' => $product->station_id,
+            'course' => $course ?: $product->course,
+            'quantity' => max(1, $quantity),
+            'notes' => $notes,
+            'source' => $source,
+            'unit_price_minor' => max(1, $product->price_minor + (int) $chosen->sum('price_delta_minor')),
+            'modifiers' => $chosen->map(fn ($m) => [
+                'modifier_id' => $m->id, 'name' => $m->name, 'price_delta_minor' => $m->price_delta_minor,
+            ])->all(),
+        ];
+    }
+
+    /**
+     * @param  array{product_id?: ?int, station_id?: ?int, course?: ?string, source?: string, name: string, unit_price_minor: int, quantity?: int, notes?: ?string, modifiers?: list<array{modifier_id?: ?int, name: string, price_delta_minor?: int}>}  $line
      */
     public function addLine(PosSale $sale, array $line): PosSaleLine
     {
@@ -138,6 +171,7 @@ class PosSaleService
             'line_total_minor' => $unit * $qty,
             'position' => $position,
             'kitchen_state' => PosSaleLine::KITCHEN_NEW,
+            'source' => $line['source'] ?? 'staff',
             'notes' => isset($line['notes']) ? trim((string) $line['notes']) ?: null : null,
             'course' => $line['course'] ?? null,
         ]);