fix: resolve ESLint errors — remove unused imports and dead code

packages/backend/src/db/seeds/music-store-seed.ts

@@ -950,17 +950,6 @@ async function seedInventory(sql: any) {
   console.log('  Inventory seed complete.')
 }
 
-// Returns dates (YYYY-MM-DD) for every occurrence of `dayOfWeek` (0=Sun)
-// starting from `startDate`, for `count` weeks.
-function weeklyDates(startDate: string, dayOfWeek: number, count: number): string[] {
-  const d = new Date(startDate + 'T12:00:00Z')
-  while (d.getUTCDay() !== dayOfWeek) d.setUTCDate(d.getUTCDate() + 1)
-  return Array.from({ length: count }, (_, i) => {
-    const nd = new Date(d)
-    nd.setUTCDate(nd.getUTCDate() + i * 7)
-    return nd.toISOString().split('T')[0]
-  })
-}
 
 async function seedLessons(sql: any) {
   console.log('\nSeeding lessons data...')