Add Tryorama end-to-end test harness

[Tristan-Stoltz-ERC]

We have 4 Tryorama test files (commons, civic, finance, cross-hApp) with validated payloads but they need a running conductor to execute.

Requirements

Set up a CI-friendly Tryorama harness that:

• Downloads the correct Holochain version
• Builds hApp bundles
• Runs multi-agent E2E scenarios
• Catches cross-cluster integration bugs that unit tests miss

Existing test files

The 4 test files have validated payloads ready to use. The harness needs to orchestrate conductor lifecycle and hApp installation.

CI considerations

• Holochain conductor startup time (~5-10s)
• Multi-agent scenarios require multiple conductors
• Test isolation between scenarios