Production-ready overhaul: backend fixes, claim flow polish, SEO, mobile, nginx

Backend:
- Fix activity score (followersCount check), NIP-98 URL proto, wallet balance guard
- Add payment_hash to confirm response, spentTodaySats to stats
- Add idx_claims_ip_hash; security headers, graceful shutdown, periodic nonce cleanup

Frontend:
- Remove 8 legacy components; polish wizard (rules summary, profile card, confetti, share)
- Stats budget bar uses spentTodaySats; ErrorBoundary with reload

SEO & production:
- Full meta/OG/Twitter, favicon, JSON-LD, robots.txt, sitemap.xml
- Mobile CSS fixes; nginx static dist + gzip + cache + security headers
- Vite manualChunks; aria-labels, dynamic page titles

Made-with: Cursor

backend/src/services/eligibility.ts

@@ -54,7 +54,7 @@ export async function checkEligibility(pubkey: string, ipHash: string): Promise<
     };
   }
 
-  if (balanceSats < config.faucetMinSats) {
+  if (balanceSats < config.minWalletBalanceSats) {
     return {
       eligible: false,
       denialCode: "insufficient_balance",

backend/src/services/nostr.ts

@@ -101,7 +101,8 @@ export async function fetchAndScorePubkey(pubkey: string, forceRefreshProfile =
   if (hasMetadata) score += 10;
   if (notesInLookback >= config.minNotesCount) score += 20;
   if (followingCount >= config.minFollowingCount) score += 10;
-  if (0 >= config.minFollowersCount) score += 10; // followers not fetched for MVP; treat as 0
+  const followersCount = 0; // followers not fetched for MVP
+  if (followersCount >= config.minFollowersCount) score += 10;
 
   let lightning_address: string | null = null;
   let name: string | null = null;