Add end-to-end CLI integration fixture flow tests

[danbot315]

Create e2e fixtures that exercise real CLI flow.

Scope

• run: init -> add -> TypeScript authoring scaffold checks -> synth
• assert generated wrappers + workflow YAML outputs
• run in CI as stable integration job

Acceptance Criteria

• deterministic test fixtures
• regressions in command flow are caught in CI

[danbot315]

Starting now: implementing initial TypeScript starter templates (Node library, Bun app, monorepo) with synth-ready defaults and docs.