fix: make GAN harness score parsing portable

scripts/gan-harness.sh

@@ -61,11 +61,18 @@ phase()  { echo -e "\n${PURPLE}════════════════
 extract_score() {
   # Extract the TOTAL weighted score from a feedback file
   local file="$1"
-  # Look for **TOTAL** or **X.X/10** pattern
-  grep -oP '(?<=\*\*TOTAL\*\*.*\*\*)[0-9]+\.[0-9]+' "$file" 2>/dev/null \
-    || grep -oP '(?<=TOTAL.*\|.*\| \*\*)[0-9]+\.[0-9]+' "$file" 2>/dev/null \
-    || grep -oP 'Verdict:.*([0-9]+\.[0-9]+)' "$file" 2>/dev/null | grep -oP '[0-9]+\.[0-9]+' \
-    || echo "0.0"
+  awk '
+    /\*\*TOTAL\*\*/ || /Verdict:/ {
+      if (match($0, /[0-9]+[.][0-9]+/)) {
+        print substr($0, RSTART, RLENGTH)
+        found = 1
+        exit
+      }
+    }
+    END {
+      if (!found) print "0.0"
+    }
+  ' "$file" 2>/dev/null
 }
 
 score_passes() {
@@ -241,8 +248,12 @@ done
 
 phase "PHASE 3: Build Report"
 
-FINAL_SCORE="${SCORES[-1]:-0.0}"
 NUM_ITERATIONS=${#SCORES[@]}
+if [ "$NUM_ITERATIONS" -gt 0 ]; then
+  FINAL_SCORE="${SCORES[$((NUM_ITERATIONS - 1))]}"
+else
+  FINAL_SCORE="0.0"
+fi
 ELAPSED=$(elapsed)
 
 # Build score progression table

tests/gan-harness.test.js

@@ -0,0 +1,74 @@
+/**
+ * Regression tests for the standalone GAN harness helpers.
+ */
+
+'use strict';
+
+const assert = require('assert');
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const { spawnSync } = require('child_process');
+
+const repoRoot = path.resolve(__dirname, '..');
+const harnessPath = path.join(repoRoot, 'scripts', 'gan-harness.sh');
+const harnessSource = fs.readFileSync(harnessPath, 'utf8');
+
+let passed = 0;
+let failed = 0;
+
+function test(name, fn) {
+  try {
+    fn();
+    console.log(`  ✓ ${name}`);
+    passed += 1;
+  } catch (error) {
+    console.log(`  ✗ ${name}`);
+    console.log(`    Error: ${error.message}`);
+    failed += 1;
+  }
+}
+
+function extractScore(feedback) {
+  const functionMatch = harnessSource.match(/extract_score\(\) \{[\s\S]*?\n\}/);
+  assert.ok(functionMatch, 'expected scripts/gan-harness.sh to define extract_score');
+
+  const temporaryDirectory = fs.mkdtempSync(path.join(os.tmpdir(), 'ecc-gan-harness-'));
+  const feedbackPath = path.join(temporaryDirectory, 'feedback.md');
+  fs.writeFileSync(feedbackPath, feedback, 'utf8');
+
+  try {
+    const result = spawnSync(
+      '/bin/bash',
+      ['-c', `${functionMatch[0]}\nextract_score "$1"`, 'gan-harness-score-test', feedbackPath],
+      { encoding: 'utf8' }
+    );
+    assert.strictEqual(result.status, 0, result.stderr || 'extract_score failed');
+    return result.stdout.trim();
+  } finally {
+    fs.rmSync(temporaryDirectory, { recursive: true, force: true });
+  }
+}
+
+console.log('\n=== GAN harness helpers ===\n');
+
+test('extract_score reads the documented TOTAL table format', () => {
+  assert.strictEqual(extractScore('| **TOTAL** | | | **7.5** |\n'), '7.5');
+});
+
+test('extract_score reads the compact TOTAL format', () => {
+  assert.strictEqual(extractScore('**TOTAL** | **8.3**\n'), '8.3');
+});
+
+test('extract_score reads a Verdict score', () => {
+  assert.strictEqual(extractScore('Verdict: PASS with score 9.1\n'), '9.1');
+});
+
+test('final score lookup is compatible with the macOS Bash 3.2 runtime', () => {
+  assert.ok(!harnessSource.includes('SCORES[-1]'), 'negative array subscripts require Bash 4.3+');
+});
+
+console.log(`\nPassed: ${passed}`);
+console.log(`Failed: ${failed}`);
+
+process.exit(failed > 0 ? 1 : 0);