feat(ui): add dark theme and formatted wallet balance input
Summary
Add persistent light and dark themes with system-preference fallback.
Introduce semantic CSS and Tailwind tokens for theme-aware colors, borders, shadows, badges, and icons.
Add accessible theme toggles globally and on the profile page.
Synchronize the selected theme with ZMP UI, browser color scheme, and theme metadata.
Update shared components and application pages for consistent dark-mode rendering.
Format wallet balance input with thousands separators and localized decimal display while preserving the normalized value for validation and API requests.
Update the style guide and design-system documentation for the new theme architecture.
Check out, review, and merge locally
Step 1.
Fetch and check out the branch for this merge request
