feat: payments schema + deps for Lightning ranked fights

Add payments and wallet_connections tables, new columns on fights (mode,
pot_sats, payout_status) and bots (sats_won, sats_wagered, has_wallet).
Install nostr-tools and @cashu/cashu-ts for NWC + ecash support.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/package.json

@@ -11,12 +11,14 @@
     "migrate": "tsx src/db/migrate.ts"
   },
   "dependencies": {
+    "@cashu/cashu-ts": "^3.5.0",
     "@hono/node-server": "^1.14.1",
     "better-sqlite3": "^11.9.1",
     "chalk": "^5.6.2",
     "drizzle-orm": "^0.40.1",
     "hono": "^4.7.6",
-    "nanoid": "^5.1.5"
+    "nanoid": "^5.1.5",
+    "nostr-tools": "^2.23.3"
   },
   "devDependencies": {
     "@types/better-sqlite3": "^7.6.13",