fix: use unified Prisma CLI when available

[AmanVarshney01]

Purpose of change

Use Prisma 8's unified Composer command when available so apps with shared ORM and Composer config can deploy from GitHub Actions.

What's changed and why

• Probe the local Prisma CLI for the composer command after dependencies are installed.
• Prefer bun run --bun prisma composer when supported. This CLI registers both the orm and composer sections from prisma.config.ts.
• Keep the existing local prisma-composer and bunx paths for repositories without the unified command.
• Cover the new command selection with a unit test.

Testing notes / Before-after

• Before: the Prisma 8 TanStack template failed with CLI.CONFIG_UNKNOWN_SECTION because standalone prisma-composer rejected the orm section.
• After: bun run --bun prisma composer deploy module.ts reads the same config and completes provisioning.
• Failed run: https://github.com/AmanVarshney01/tanstack-start-muaahhh/actions/runs/32366362237/job/96416620692
• node --test tests/*.test.mjs — 44 tests passed.
• Confirmed Prisma 6 returns a non-zero status for prisma composer --help, so it stays on the existing fallback.

Rollout

• Move the v1 tag to the merged commit. Existing generated workflows use prisma/cloud-deploy-action@v1.