feat: remove FPX, add UK charity persona features

- Remove FPX payment rail entirely (Malaysian, not UK)
- Add volunteer portal (/v/[code]) with live pledge tracking
- Add public event page (/e/[slug]) with progress bar + social proof
- Add fundraiser leaderboard (/dashboard/events/[id]/leaderboard)
- Add WhatsApp share buttons on confirmation, bank instructions, volunteer view
- Enhanced Gift Aid UX with +25% bonus display and HMRC declaration text
- Gift Aid report export (HMRC-ready CSV filter)
- Volunteer view link + WhatsApp share on QR code cards
- Updated home page: 4 personas, 3 UK payment rails, 8 features
- Public event API endpoint with privacy-safe donor name truncation
- Volunteer API with stats, conversion rate, auto-refresh

.gitignore

@@ -1,16 +1,7 @@
 node_modules/
-__pycache__/
-*.pyc
-.DS_Store
-*.swp
-*.swo
-
-# API keys — never commit real credentials
-.env
-
 .pi/agent-sessions/
-
-
+calvana.tar.gz
+*.tmp
+nul
+.env
 .playwright-cli/
-
-tmp/