Fix 3 bugs: participant branch, layout update, receipt branch

1. ParticipantForm: set branch_id from session in mount() so new
   participants get the active branch (was null, invisible in list)
2. SpaceLayoutService::update: compare config BEFORE updating the model
   so change detection works (was comparing same value to itself)
3. ReceiptSettings: use session branch_id instead of user->branch_id
   which could be null, preventing template save
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Domain/Facility/Services/SpaceLayoutService.php

@@ -40,12 +40,14 @@ public function update(SpaceLayout $layout, array $data): SpaceLayout
             $oldType = $layout->layout_type->value;
             $oldConfig = $layout->layout_config;
 
-            $layout->update($data);
-
             $newType = $data['layout_type'] ?? $oldType;
             $newConfig = $data['layout_config'] ?? $oldConfig;
 
-            if ($newType !== $oldType || $newConfig !== $oldConfig) {
+            $layout->update($data);
+
+            $configChanged = $newType !== $oldType || json_encode($newConfig) !== json_encode($oldConfig);
+
+            if ($configChanged) {
                 $layout->segments()->delete();
                 $this->generateSegments($layout->fresh());
             }

app/Livewire/Participants/ParticipantForm.php

@@ -50,6 +50,8 @@ class ParticipantForm extends Component
 
     public function mount(?Participant $participant = null): void
     {
+        $this->branch_id = session('active_branch_id', auth()->user()->branch_id);
+
         if ($participant && $participant->exists) {
             $this->participant = $participant->load('person');
             $this->editing = true;

app/Livewire/Settings/ReceiptSettings.php

@@ -22,8 +22,7 @@ public function mount(): void
     {
         $this->authorize('settings.manage');
 
-        $user = auth()->user();
-        $this->selectedBranchId = $user->branch_id;
+        $this->selectedBranchId = session('active_branch_id', auth()->user()->branch_id);
 
         $this->loadTemplate();
     }