fix: Remove clear form button and improve UX

Major UI/UX improvements and bug fixes:

• Fixed date formatting bug in ticket receipts (undefined dates)
• Removed clear form button per user request
• Added favicon integration across all pages (apple-touch-icon, favicon variants)
• Implemented auto-collapse for product categories after adding items
• Changed all ticket content alignment to left for better readability
• Made product interface more compact to reduce scrolling
• Enhanced date validation and formatting throughout the system

Technical changes:
- Fixed esc() function regex that was causing date corruption
- Added collapseAllCategories() function for better UX
- Updated cache-busting versions for proper browser refresh
- Improved date handling with proper validation
- Added comprehensive favicon support with web manifest

🤖 Generated with [Claude Code](https://claude.ai/code)

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

setup.html

@@ -4,6 +4,12 @@
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Configuración Inicial - AP POS</title>
+    <!-- Favicons -->
+    <link rel="apple-touch-icon" sizes="180x180" href="/src/favicon/apple-touch-icon.png">
+    <link rel="icon" type="image/png" sizes="32x32" href="/src/favicon/favicon-32x32.png">
+    <link rel="icon" type="image/png" sizes="16x16" href="/src/favicon/favicon-16x16.png">
+    <link rel="manifest" href="/src/favicon/site.webmanifest">
+    <link rel="icon" href="/src/favicon/favicon.ico">
     <link rel="stylesheet" href="styles.css">
     <style>
       body {