Fix formatting and interfaces in nearly every file

app/Models/Observers/AircraftObserver.php

@@ -11,6 +11,9 @@ use App\Support\ICAO;
  */
 class AircraftObserver
 {
+    /**
+     * @param Aircraft $aircraft
+     */
     public function creating(Aircraft $aircraft): void
     {
         if (empty($aircraft->hex_code)) {

app/Models/Observers/JournalTransactionObserver.php

@@ -4,6 +4,10 @@ namespace App\Models\Observers;
 
 use App\Models\JournalTransaction;
 
+/**
+ * Class JournalTransactionObserver
+ * @package App\Models\Observers
+ */
 class JournalTransactionObserver
 {
     /**
@@ -31,7 +35,6 @@ class JournalTransactionObserver
 
         if ($transaction['debit']) {
             $balance = $journal->balance->toAmount();
-            #$journal->balance = $journal->balance->subtract($transaction['debit']);
             $journal->balance = (int) $balance - $transaction->debit;
         }
 

app/Models/Observers/SettingObserver.php

@@ -4,6 +4,10 @@ namespace App\Models\Observers;
 
 use App\Models\Setting;
 
+/**
+ * Class SettingObserver
+ * @package App\Models\Observers
+ */
 class SettingObserver
 {
     /**

app/Models/Observers/SubfleetObserver.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace App\Models\Observers;
+
+use App\Models\Subfleet;
+
+/**
+ * Class SubfleetObserver
+ * @package App\Models\Observers
+ */
+class SubfleetObserver
+{
+    /**
+     * @param Subfleet $model
+     */
+    public function creating(Subfleet $model)
+    {
+        if (!filled($model->ground_handling_multiplier)) {
+            $model->ground_handling_multiplier = 100;
+        }
+    }
+}