fix: add non-null assertion for DATABASE_URL in sync.ts closure

TypeScript doesn't narrow module-level consts across closure
boundaries, so the explicit process.exit(1) guard isn't enough —
add ! assertion at the usage site inside run().

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

scripts/sync.ts

@@ -37,7 +37,7 @@ function parseScore(score: RawScore | undefined) {
 }
 
 async function run() {
-  const client = postgres(DATABASE_URL, { max: 5 })
+  const client = postgres(DATABASE_URL!, { max: 5 })
   const db = drizzle(client)
 
   const teamCache = new Map<string, number>()