[piekstra]

Summary

Flows often carry inputs that most runs leave at their default (a tenant, a region, a fixture id). Showing all of them in the run form makes the form noisy. advanced: true keeps such an input behind More options:

inputs:
  - { name: greeting, default: hi }
  - { name: tenant, advanced: true, default: acme }

• The run form shows non-advanced inputs, plus a More options (N) button that reveals the rest (aria-expanded).
• --input tenant=globex sets an advanced input from the CLI like any other.
• lest get marks advanced inputs.
• Validation: a required advanced input needs a default, so the form can always start without opening More options.

Verification

• New validate test an_advanced_required_input_needs_a_default, new UI tests for formInputs.
• Ran a sample flow headless through lest ui with Playwright: closed form shows greeting and More options (2); opened, it shows greeting | Tenant | region.
• lest run hello --input tenant=globex --input region=us passes.
• make lint, make build, UI tests and all Rust tests pass except parallel_group_runs_concurrently and cancel_stops_steps_but_runs_finally_and_cleanup, which fail the same way on main on this machine under load (timing assertions); CI is the reference.

[piekstra]

Review pass on the diff (self-review; no findings needing a change):

• A required advanced input without a default would leave Run disabled with the field hidden. Prevented in validation rather than in the form, so every client (UI, CLI) sees the same rule.
• The More options button only renders when the flow has advanced inputs, so flows without them look unchanged.
• Advanced is presentation only: the run request, CLI --input and the report treat these inputs like any other.