feat(system-builder): rests for the examples and genre starters (4f6b)

[over2take]

As approved (docs/mockups/builder-rests.html, decision 8). The game examples copy their built-in rest buttons, each resource kept in a new RESOURCES stat: CWN's long rest takes 1 System Strain off (system_strain, as the built-in names it), Cyberpunk RED's end of session sets LUCK points back to LUCK, Shadowrun's sets Edge points back to Edge. The starters suit their genre: Sword & Spell heals 1d8 + CON mod on a short rest and everything plus exhaustion on a long one; Starfarer gives a wound back after a short rest and all of them after a long one; Story First turns the short and long rests off, clears harm and exhaustion in a Downtime of its own, and ends fear with the scene. The built-in games themselves are unchanged. The example cards' stat counts (and their tests) gain the one stat each.

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