Fix Bootstrap light/dark theming across all layouts

- Make dark mode toggle reactive using Alpine x-data theme property
- Apply saved theme on page load via data-bs-theme attribute binding
- Remove hardcoded bg-light classes that broke dark mode styling
- Fix duplicate/broken Bootstrap bundle import in app.js

resources/views/livewire/auth/login.blade.php

@@ -29,7 +29,7 @@ new #[Layout('components.layouts.guest')] class extends Component {
 }
 ?>
 
-<div class="min-vh-100 d-flex align-items-center justify-content-center bg-light">
+<div class="min-vh-100 d-flex align-items-center justify-content-center">
     <div class="card shadow-sm" style="width: 100%; max-width: 420px;">
         <div class="card-body p-4">
             <div class="text-center mb-4">

resources/views/livewire/travel-request/create.blade.php

@@ -318,7 +318,7 @@ new #[Layout('components.layouts.app')] class extends Component {
                 @error('journeys') <div class="alert alert-danger">{{ $message }}</div> @enderror
 
                 @foreach ($journeys as $i => $journey)
-                    <div class="border rounded p-3 mb-3 bg-light" wire:key="journey-{{ $i }}">
+                    <div class="border rounded p-3 mb-3" wire:key="journey-{{ $i }}">
                         <div class="d-flex justify-content-between align-items-center mb-2">
                             <strong class="small">Journey {{ $i + 1 }}</strong>
                             @if (count($journeys) > 1)
@@ -413,7 +413,7 @@ new #[Layout('components.layouts.app')] class extends Component {
             </div>
             <div class="card-body">
                 @foreach ($costCodes as $i => $code)
-                    <div class="border rounded p-3 mb-3 bg-light" wire:key="code-{{ $i }}">
+                    <div class="border rounded p-3 mb-3" wire:key="code-{{ $i }}">
                         <div class="d-flex justify-content-between align-items-center mb-2">
                             <strong class="small">Cost Code {{ $i + 1 }}</strong>
                             @if (count($costCodes) > 1)