feat: comprehensive vendor settings overhaul with Company inheritance

- Add structured API response with business_info, localization, letzshop,
  invoice_settings, theme_settings, domains, and stripe_info sections
- Add PUT /vendor/settings/business-info with reset_to_company capability
- Add PUT /vendor/settings/letzshop with validation for tax rates, delivery
- Add 9 settings sections: General, Business Info, Localization, Marketplace,
  Invoices, Branding, Domains, API & Payments, Notifications
- Business Info shows "Inherited" badges and Reset buttons for company fields
- Marketplace section includes Letzshop CSV URLs and feed options
- Read-only sections for Invoices, Branding, Domains, API with contact support
- Add globe-alt icon for Domains section
- Document email templates architecture for future implementation

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

static/shared/js/icons.js

@@ -93,6 +93,7 @@ const Icons = {
     'chat': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 12h.01M12 12h.01M16 12h.01M21 12c0 4.418-4.03 8-9 8a9.863 9.863 0 01-4.255-.949L3 20l1.395-3.72C3.512 15.042 3 13.574 3 12c0-4.418 4.03-8 9-8s9 3.582 9 8z"/></svg>`,
     'bell': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15 17h5l-1.405-1.405A2.032 2.032 0 0118 14.158V11a6.002 6.002 0 00-4-5.659V5a2 2 0 10-4 0v.341C7.67 6.165 6 8.388 6 11v3.159c0 .538-.214 1.055-.595 1.436L4 17h5m6 0v1a3 3 0 11-6 0v-1m6 0H9"/></svg>`,
     'inbox': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M20 13V6a2 2 0 00-2-2H6a2 2 0 00-2 2v7m16 0v5a2 2 0 01-2 2H6a2 2 0 01-2-2v-5m16 0h-2.586a1 1 0 00-.707.293l-2.414 2.414a1 1 0 01-.707.293h-3.172a1 1 0 01-.707-.293l-2.414-2.414A1 1 0 006.586 13H4"/></svg>`,
+    'paper-airplane': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 19l9 2-9-18-9 18 9-2zm0 0v-8"/></svg>`,
 
     // Files & Documents
     'document': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 12h6m-6 4h6m2 5H7a2 2 0 01-2-2V5a2 2 0 012-2h5.586a1 1 0 01.707.293l5.414 5.414a1 1 0 01.293.707V19a2 2 0 01-2 2z"/></svg>`,
@@ -119,6 +120,7 @@ const Icons = {
     // Location
     'location-marker': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M17.657 16.657L13.414 20.9a1.998 1.998 0 01-2.827 0l-4.244-4.243a8 8 0 1111.314 0z"/><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15 11a3 3 0 11-6 0 3 3 0 016 0z"/></svg>`,
     'globe': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M3.055 11H5a2 2 0 012 2v1a2 2 0 002 2 2 2 0 012 2v2.945M8 3.935V5.5A2.5 2.5 0 0010.5 8h.5a2 2 0 012 2 2 2 0 104 0 2 2 0 012-2h1.064M15 20.488V18a2 2 0 012-2h3.064M21 12a9 9 0 11-18 0 9 9 0 0118 0z"/></svg>`,
+    'globe-alt': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M21 12a9 9 0 01-9 9m9-9a9 9 0 00-9-9m9 9H3m9 9a9 9 0 01-9-9m9 9c1.657 0 3-4.03 3-9s-1.343-9-3-9m0 18c-1.657 0-3-4.03-3-9s1.343-9 3-9m-9 9a9 9 0 019-9"/></svg>`,
 
     // Status & Indicators
     'exclamation': `<svg class="{{classes}}" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M12 9v2m0 4h.01m-6.938 4h13.856c1.54 0 2.502-1.667 1.732-3L13.732 4c-.77-1.333-2.694-1.333-3.464 0L3.34 16c-.77 1.333.192 3 1.732 3z"/></svg>`,