feat(steps): one reply box per outcome

A reply's identity is its status, not its call: a handler answering 200 or 401 draws two boxes (id per function, response, status), so each line from the handler carries its own condition on the picture — the Screens view's idiom — and the anchor's Leads-to list reads as the contract; replies whose status the code does not spell out share one box labelled by the call. Panel note, spec §3.13, CHANGELOG, plan; servers test asserts the ASP.NET and Spring outcomes per box.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01REFyW9hmNrxhwN5wxRoAkC

ui/src/views/StepsView.svelte

@@ -635,7 +635,7 @@
           <p class="dim note mono">{selectedInfo.step.effect.apis.join(' · ')}</p>
         {/if}
         {#if selectedInfo.step.effect?.category === 'response'}
-          <p class="dim note">The endpoint’s contract as the code has it: each row below is one way it answers, with the condition it answers under.</p>
+          <p class="dim note">{selectedInfo.step.effect.statuses?.length ? 'One way the endpoint answers — each row below is a site that sends it, with the condition it answers under; its other outcomes are the boxes beside it.' : 'Replies whose status the code does not spell out — each row below is one, with the condition it answers under.'}</p>
         {/if}
         {#if selectedInfo.step.events && selectedInfo.step.events.length > 1}
           <p class="dim note mono">⇠ {selectedInfo.step.events.join(' · ')}</p>