Wallet-less sign-up fails on a Postgres volume from before #272 #274

Description

The wallet-less example's sign-up returns 502 on a Postgres volume created before #272. server/compose.yaml keeps the source repo's volume name (walletless_walletless-pg), but server/src/db/schema.sql dropped the ledger_user_id TEXT NOT NULL column. The server applies the schema with CREATE TABLE IF NOT EXISTS, so an old users table keeps that column and every insert fails.

Steps to reproduce

1. In BootNodeDev/canton-dappbooster-walletless, run ./scripts/dev-stack.sh up
2. Run ./scripts/dev-stack.sh down
3. In this repo, run pnpm dev:amulet-vesting-walletless up
4. Open http://localhost:3012 and create an account
5. See the sign-up fail

Expected vs actual behavior

Expected: the account is created
Actual: 502 with null value in column "ledger_user_id" of relation "users" violates not-null constraint

Additional context

• Each failed attempt still allocates a party and grants the server's participant user one of its 1000 rights
• try:clean leaves the wallet-less example's Postgres volume behind #271 does not cover it: its stack:reset runs only from try:clean
• Workaround: docker compose -f server/compose.yaml down -v, which deletes the accounts
• Found while reviewing feat(examples): add the wallet-less amulet vesting example #272