Phase 13: Accessibility and polish pass

[elfensky]

Summary

Comprehensive accessibility and polish pass on the loadout builder.

Parent: #162

Checklist

• Keyboard navigation for stratagem picker grid (arrow keys + Enter)
• aria-label and role on all interactive elements
• Focus management (focus → picker on open, back to slot on close)
• Escape key closes all pickers/dropdowns
• aria-expanded on dropdowns
• Mobile touch targets minimum 44x44px
• Loading/empty states for favorites list
• Proper <title> and meta description for both pages
• Umami data-umami-event with loadout- prefix on all interactions

Files

• MODIFY src/features/loadout/StratagemPicker.jsx
• MODIFY src/features/loadout/ItemDropdown.jsx
• MODIFY src/features/loadout/LoadoutBuilder.jsx
• MODIFY src/features/loadout/LoadoutBuilder.css

Size: M