Fix non-empty criterion check to use artifact.body instead of text

The non-empty check in scoreArtifactQuality was using text (which
includes appended context) instead of artifact.body. This meant an
artifact with an empty body would pass the non-empty check whenever
context was supplied, defeating the purpose of the validity check.

Restored the check to use artifact.body.length so context informs
quality scoring but cannot substitute for actual artifact content.

Author: cursoragent

workers/src/orchestrate.ts

@@ -425,7 +425,7 @@ function scoreArtifactQuality(
   for (const c of criteria) {
     const ck = c.check.toLowerCase();
     let passed = false;
-    if (ck.includes("non-empty")) passed = artifact.fields.length > 3 || text.length > 0;
+    if (ck.includes("non-empty")) passed = artifact.fields.length > 3 || artifact.body.length > 0;
     else if (ck.includes("10")) passed = text.split(/\s+/).length >= 10;
     else if (ck.includes("number") || ck.includes("concrete")) passed = /\d/.test(text);
     else if (ck.includes("interpretation") || ck.includes("does not contain")) passed = !/should|better|worse|means|implies/i.test(artifact.body);