feat(system builder 2b): one bank account per player per game system,…

[over2take]

… with a database copy first

bank_accounts replaces the one-bank-per-player player_banks, which is kept untouched as the record. Every bank read and write goes through bank/accounts.js, scoped to the running system (a sheet's cash field shows its own system's account), and waits for the one-time move to finish - browsers reconnect within milliseconds of a restart, and an empty account opened first would block a real balance from being copied in.

The move (startup/bankAccounts.js) copies the database first when the disk has room (startup/backup.js, VACUUM INTO), then copies each balance, debt and flag into every system the player has a sheet in plus the running one, in one transaction, with a marker so it runs once.

Tests: accounts kept apart, the move's rules (mutation-checked: marker, wait, systems, transaction), the copy and its space check, switching systems in play, and db.js opening a 1.14.4-shaped file. The 15 test files that seeded player_banks now use the running system's account. Verified on a read-only copy of the real database: 21 banks into 29 accounts, every value identical.

Summary

Test plan

• Tested locally
• Tests pass

Pre-merge checklist

Code quality:

• Code follows project style
• No breaking changes (or clearly documented)
• No console errors or warnings

Version & Release:

• Version bumped? If releasing to users, update:
  • frontend/package.json version
  • docker-compose.yml APP_VERSION
  • CHANGELOG.md with release notes
• GitHub Actions will auto-tag Docker images with the new version

Before merging to main:

• All tests passing
• PR reviewed and approved
• Branch is up to date with main
• No merge conflicts

Related issues