v1.0.2 — receipts survive red goldens

The receipt survives the red case. A failing nika test golden used to abort the composite before the render — no comment exactly when the reviewer needed one. The test lane now captures the exit, renders golden test FAILED (exit N) into the sticky comment/step summary, and the final gate fires on check + golden combined.

Unknown modes are refused by name. mode: run no longer silently narrows to check-only — execution is not this action's job, and the refusal says so (::error, exit 1).

The test lane proves itself in CI. Tracked offline fixture (fixtures/input.txt + golden, mock provider, zero keys) + two new e2e steps: golden lane green, unknown mode refused.

Chainable outputs documented: clean · cost-floor · cost-unbounded — always consume the floor with its unbounded flag, never the bare number.

- uses: supernovae-st/nika-action@v1
  with:
    workflow: flows/daily-brief.nika.yaml

Full details: #1