chore(db): drop dead seed-passwords script

seed-passwords.ts shipped with an empty seedUsers array, so
db:seed-passwords was a no-op. Real seeding lives in db:seed
(src/db/seed.ts), which sets up users, courses, questions, and
assignments — and which this script is now removed in favor of.

Removes the script, the npm task, and updates CLAUDE.md.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: WangYuTengg

CLAUDE.md

@@ -29,7 +29,7 @@ npm run build:server     # Server only
 npm run db:generate      # Generate migration from schema changes
 npm run db:migrate       # Apply migrations
 npm run db:studio        # Open Drizzle Studio
-npm run db:seed-passwords # Seed test user passwords
+npm run db:seed          # Seed users, courses, questions, assignments
 
 # Lint
 npm run lint             # ESLint (no auto-fix)

package.json

@@ -18,7 +18,6 @@
     "db:migrate": "tsx src/db/migrate.ts",
     "db:push": "drizzle-kit push",
     "db:studio": "drizzle-kit studio",
-    "db:seed-passwords": "tsx src/db/seed-passwords.ts",
     "db:seed": "tsx src/db/seed.ts",
     "db:seed-submissions": "tsx src/db/seed-submissions.ts",
     "db:reset": "tsx src/db/reset.ts",