Add youaskm3 Phase 2 smoke test

[enricopiovesan]

Summary

Add a deterministic Phase 2 smoke test that proves the full youaskm3 setup path: app validate → app register → runtime loads → workflow executes → output rendered.

Why

Phase 2 has no automated verification without this. The smoke test is the only way to know the CLI registration path actually works end-to-end.

Definition of Done

• Smoke runs traverse-cli app validate and asserts exit 0
• Smoke runs traverse-cli app register and asserts durable workspace state written
• Smoke starts runtime and confirms registered workflow is discoverable
• Smoke executes workflow via HTTP API and asserts output
• Exits 0 on pass, exits 1 with diagnostics on fail
• Added to scripts/ci/ and referenced in nightly workflow

Governing specs

• 044-application-bundle-manifest (approved)
• 046-public-cli-app-registration (approved)
• 033-http-json-api (approved)

Depends on

#16 (Phase 2 registration), #15 (Phase 1 smoke)