v1.0.62 — Platform monetization: listing fees for paid events & Lab profiles

NEW: usePlatformFee hook — central fee configuration
- PLATFORM_FEES.featuredEvent = 5,000 sats (paid/ticketed events)
- PLATFORM_FEES.labProfile = 5,000 sats (coaches/filmers/editors with a rate)
- PLATFORM_FEES.featuredShop = 10,000 sats (reserved for future use)
- 30-day validity stored in localStorage per fee type
- Platform owner pubkeys always bypass fees automatically

NEW: PlatformFeePayment component — generic, reusable payment gate
- Auto-pay via connected NWC or WebLN wallet
- QR code fallback for manual Lightning payment
- Shows "Active — X days remaining" when fee is already paid
- Branded gradient UI consistent with SkateSpots design system
- All fees go to skatespots@minibits.cash

FEATURE: CreateEventPage — entry fee field
- New "Entry Fee" input field (optional)
- When filled, triggers 5,000 sat platform listing fee gate
- Entry fee stored as event tag for display on event detail page
- Free events: zero friction, no fee required

FEATURE: BecomeCoachPage — monetized profile fee
- When "Rate" field is filled, 5,000 sat listing fee required
- Submit button locked with clear message until fee paid
- Free/volunteer coaches: zero friction

FEATURE: BecomeFilmerPage — same as coach
FEATURE: BecomeEditorPage — same as coach

RULE: "You only pay when you earn" — free profiles and free events
always publish instantly with zero fees.