perf: SQLite WAL mode and indexes

Add PRAGMA synchronous=NORMAL, temp_store=MEMORY, mmap_size=256MB for
better write throughput and query performance. Create 11 indexes on
commonly queried columns (fights.status, fights.created_at, bots.elo,
rounds.fight_id, payments, tournament_matches). Run PRAGMA optimize
on startup for query planner statistics.

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

server/src/db/index.ts

@@ -12,6 +12,9 @@ mkdirSync(dirname(dbPath), { recursive: true })
 const sqlite = new Database(dbPath)
 sqlite.pragma('journal_mode = WAL')
 sqlite.pragma('foreign_keys = ON')
+sqlite.pragma('synchronous = NORMAL')
+sqlite.pragma('temp_store = MEMORY')
+sqlite.pragma('mmap_size = 268435456') // 256MB memory-mapped I/O
 
 export const db = drizzle(sqlite, { schema })
 export { schema, sqlite }

server/src/db/startup.ts

@@ -160,5 +160,23 @@ export function runMigrations() {
     sqlite.exec("UPDATE bots SET bot_type = 'classic' WHERE webhook_url LIKE 'http://classic.local%' AND bot_type = 'regular'")
   } catch { /* ok */ }
 
+  // Indexes for common query patterns
+  sqlite.exec(`
+    CREATE INDEX IF NOT EXISTS idx_fights_status ON fights(status);
+    CREATE INDEX IF NOT EXISTS idx_fights_created ON fights(created_at);
+    CREATE INDEX IF NOT EXISTS idx_fights_bot_a ON fights(bot_a_id);
+    CREATE INDEX IF NOT EXISTS idx_fights_bot_b ON fights(bot_b_id);
+    CREATE INDEX IF NOT EXISTS idx_bots_elo ON bots(elo_rating);
+    CREATE INDEX IF NOT EXISTS idx_bots_tier ON bots(tier);
+    CREATE INDEX IF NOT EXISTS idx_bots_active ON bots(is_active);
+    CREATE INDEX IF NOT EXISTS idx_rounds_fight ON rounds(fight_id);
+    CREATE INDEX IF NOT EXISTS idx_payments_status ON payments(status);
+    CREATE INDEX IF NOT EXISTS idx_payments_bot ON payments(bot_id);
+    CREATE INDEX IF NOT EXISTS idx_tournament_matches_tournament ON tournament_matches(tournament_id);
+  `)
+
+  // Run PRAGMA optimize on startup for query planner stats
+  sqlite.pragma('optimize')
+
   logger.info('db', 'database migrated')
 }