fix: emit real checkpoint artifact for wrapper integration

scripts/long_task_governor_wrapper.mjs

@@ -1,5 +1,6 @@
 #!/usr/bin/env node
 import fs from 'fs';
+import path from 'path';
 
 function fail(code, message) {
   process.stderr.write(`${code}: ${message}\n`);
@@ -124,6 +125,35 @@ function toSlug(value) {
     .slice(0, 48);
 }
 
+function ensureCheckpointArtifact(externalizedCheckpointPath, input, classificationResult) {
+  if (classificationResult.classification !== 'long_task') return null;
+  if (!classificationResult.silentCandidate) return null;
+  if (!externalizedCheckpointPath) return null;
+
+  const artifactPath = path.resolve(process.cwd(), externalizedCheckpointPath);
+  const artifact = {
+    kind: 'long_task_checkpoint',
+    triggerKind: input.triggerKind || 'artifact',
+    checkpointTrigger: input.checkpointTrigger || '',
+    currentStep: input.currentStep || '',
+    nextStep: input.nextStep || '',
+    waitingOn: input.waitingOn || '',
+    blocker: input.blocker || '',
+  };
+
+  fs.mkdirSync(path.dirname(artifactPath), { recursive: true });
+  fs.writeFileSync(artifactPath, JSON.stringify(artifact, null, 2) + '\n', 'utf8');
+
+  const stats = fs.statSync(artifactPath);
+  const readable = fs.readFileSync(artifactPath, 'utf8');
+
+  return {
+    absolutePath: artifactPath,
+    bytes: stats.size,
+    readable: readable.trim().length > 0,
+  };
+}
+
 function buildExternalizedCheckpointPath(input, classificationResult) {
   if (classificationResult.classification !== 'long_task') return '';
   if (!classificationResult.silentCandidate) return '';
@@ -138,14 +168,16 @@ function buildExternalizedCheckpointPath(input, classificationResult) {
   return `checkpoints/${stableSeed}.json`;
 }
 
-function buildProgressEvidence(input, classificationResult, externalizedCheckpointPath) {
+function buildProgressEvidence(input, classificationResult, externalizedCheckpointPath, checkpointArtifact) {
   if (classificationResult.classification !== 'long_task') return null;
   if (!classificationResult.silentCandidate) return null;
   if (!externalizedCheckpointPath) return null;
+  if (!checkpointArtifact || checkpointArtifact.readable !== true) return null;
 
   return {
     sessionKey: toSlug([input.currentStep, input.waitingOn, input.nextStep].filter(Boolean).join('-')) || 'long-task-session',
     checkpointPath: externalizedCheckpointPath,
+    verificationResult: `checkpoint artifact readable at ${externalizedCheckpointPath}`,
   };
 }
 
@@ -197,7 +229,8 @@ function main() {
   const classificationResult = classify(input);
   const taskRecord = bootstrapTaskState(input, classificationResult);
   const externalizedCheckpointPath = buildExternalizedCheckpointPath(input, classificationResult);
-  const progressEvidence = buildProgressEvidence(input, classificationResult, externalizedCheckpointPath);
+  const checkpointArtifact = ensureCheckpointArtifact(externalizedCheckpointPath, input, classificationResult);
+  const progressEvidence = buildProgressEvidence(input, classificationResult, externalizedCheckpointPath, checkpointArtifact);
   const silentLaunch = validateSilentLaunch(input, classificationResult);
   const handoff = planHandoff(classificationResult);
 
@@ -210,6 +243,7 @@ function main() {
     taskRecord,
     progressEvidence,
     externalizedCheckpointPath,
+    checkpointArtifact,
     silentLaunchOk: silentLaunch.ok,
     silentLaunchReason: silentLaunch.reason,
     recommendedFallback: silentLaunch.recommendedFallback,