Run outcomes: refusal and no-op must not report bare Succeeded

Today a stage-gate refusal still reports `Succeeded` — #96 fixed cancels only. Define the outcome contract — refused / failed / succeeded / succeeded-with-no-changes — and surface it on run status for the UI. Frame it as an extension of ADR 0011's exit-code contract: exit 2 → `LimitReached` (#119) is the precedent; a refusal wants the same shape, not a bespoke channel. Related hook: the "results pushed" notice overstates outcomes the same way — flagged in PR #114.

Done when:
- E2E shows a refused gate ≠ `Succeeded`.
- A no-change run is distinguishable from a changed one.

Depends on: #119 (rides the same termination mechanism).

Start with ADR 0011 and issue #119 to understand the existing termination and exit-code contract, then inspect the E2E coverage for run status and the outcome reporting mentioned in PR #114. Done means a refused gate is not reported as Succeeded, and a no-change run is distinguishable from a changed run in the UI-facing status.

Written by the indexing model from the issue text.