MonoPhone

1. 👥 Social Loop — Groups Tab Redesign
Complete redesign of the Groups tab with real backend integration and a cleaner monochromatic UI.

Real User Data — Leaderboard now fetches actual registered users from the backend API instead of stub data
Weekly / Monthly Sub-tabs — Toggle between weekly focus rankings (thisweek) and monthly cumulative rankings (overall)
Groups Feed — Minimalist "Groups" header with + create button and "Join Group" text toggle
Inline Join Flow — 4-character alphanumeric invite code input with instant validation
Group Detail View — Tap any group to open its detail screen with two sub-tabs:
Leaderboard — Rank-ordered list showing weekly focus time per member (#1 | username | 410m)
Share — Bold invite code display, QR placeholder, and native share sheet integration (share_plus)
Real API Wiring — All group CRUD, member listings, and rankings now call the real backend endpoints (/groups, /rankings, /user/profile)

2. 🎨 Design Compliance
Pure black 0xFF000000 backgrounds with stark white 0xFFFFFFFF copy
Muted silver 0xFF757575 for secondary metadata strings
No card borders, no gradients, no colorful icons, no branding
Clean monospace typography with letter-spacing for visual hierarchy