Warm up first-screen proof script and headline for non-AI-native users

- proofScriptFor: use plain language when no source artifact is present
  (no 'Scattermind' name-dropping for raw paste users). Source-aware
  script is preserved when artifact context exists.
- firstScreen.headline: 'One thing now: [title]' replaces 'Build only
  this first: [title]' — simpler declarative for tired users.
- proof script fallback now includes a 'what happens next' sentence
  so the user knows evidence changes the decision.
- Updated check-rank-feedback.mjs headline assertion to match.

scripts/check-rank-feedback.mjs

@@ -81,7 +81,7 @@ try {
   assert.ok(data.ranked.find(item => item.id === 'bridge-contract').factors.metricHints.value === undefined);
   assert.equal(data.brief.source.artifactId, 'snapshot_123');
   assert.equal(data.brief.decisionReceipt.activeMove, data.brief.quickGlance.topPick);
-  assert.match(data.brief.firstScreen.headline, /Build only this first/);
+  assert.match(data.brief.firstScreen.headline, /One thing now/);
   assert.equal(data.brief.firstScreen.primaryAction, data.brief.decisionReceipt.firstProofStep);
   assert.equal(data.brief.firstScreen.proofQuestion, data.brief.decisionReceipt.evidenceQuestion);
   assert.equal(data.brief.firstScreen.proofScript, data.brief.decisionReceipt.proofScript);

server.js

@@ -1860,14 +1860,16 @@ function evidenceQuestionFor(option) {
 
 function proofScriptFor(option, provenance = {}) {
   if (!option) return '';
-  const sourceName = cleanText(provenance?.source || 'Scattermind', 60);
+  const sourceName = cleanText(provenance?.source || '', 60);
   const sourceLabel = cleanText(provenance?.snapshotTitle || provenance?.artifactId || '', 120);
   const evidence = evidenceQuestionFor(option);
   const next = nextStepFor(option);
-  const setup = sourceLabel
+  const hasSource = Boolean(sourceLabel && sourceName);
-    ? `I have a ${sourceName} build-order recommendation for “${sourceLabel}”.`
+  if (hasSource) {
-    : 'I am checking the next build move before adding more scope.';
+    const setup = `I have a ${sourceName} build-order recommendation for "${sourceLabel}".`;
-  return cleanText(`${setup} The proposed first move is “${option.title}”. ${next} The thing I need to learn is: ${evidence}`, 520);
+    return cleanText(`${setup} The proposed first move is "${option.title}". ${next} The thing I need to learn is: ${evidence}`, 520);
+  }
+  return cleanText(`The first move I want to test is "${option.title}". ${next} The thing I need to learn is: ${evidence}. If that produces a clear signal, the next move changes. If not, I need a different first step.`, 520);
 }
 
 function nextStepFor(option) {
@@ -1962,7 +1964,7 @@ function createDecisionBrief({ idea, context, mode, ranked, provenance, decision
   const activeSuccessSignal = carriedProofSignalFor(top, ranked, 'successSignal');
   const activeKillSignal = carriedProofSignalFor(top, ranked, 'killSignal');
   const firstScreen = top ? {
-    headline: `Build only this first: ${top.title}`,
+    headline: `One thing now: ${top.title}`,
     primaryAction: nextStepFor(top),
     proofQuestion: evidenceQuestionFor(top),
     proofScript: activeProofScript,