Fix PR comment workflow parsing on main

.github/workflows/costguard-pr-comment.yml

@@ -9,32 +9,83 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Detect analyzable files
+        id: detect
+        run: |
+          FILES=$(git diff --name-only origin/${{ github.base_ref }}...HEAD 2>/dev/null | grep -E '\.(prompt|txt|md)$' || true)
+          if [ -z "$FILES" ]; then
+            echo "skip=true" >> $GITHUB_OUTPUT
+            echo "No analyzable prompt files changed — skipping analysis."
+          else
+            echo "skip=false" >> $GITHUB_OUTPUT
+            echo "Analyzable files found:"
+            echo "$FILES"
+          fi
+
       - name: Run CostGuardAI
         id: costguard
+        if: steps.detect.outputs.skip == 'false'
         run: npx @camj78/costguardai@latest ci --fail-on-risk 70 --format json > result.json
         continue-on-error: true
 
       - name: Post PR comment
+        if: steps.detect.outputs.skip == 'false'
         uses: actions/github-script@v7
         with:
           script: |
             const fs = require('fs');
-            const data = JSON.parse(fs.readFileSync('result.json', 'utf8'));
 
-            const body = `
-❌ CostGuardAI Analysis
+            if (!fs.existsSync('result.json')) {
+              console.log('result.json not found — skipping comment.');
+              return;
+            }
+
+            let data;
+            try {
+              const raw = fs.readFileSync('result.json', 'utf8').trim();
+              if (!raw) {
+                console.log('result.json is empty — skipping comment.');
+                return;
+              }
+              data = JSON.parse(raw);
+            } catch (e) {
+              console.log('result.json could not be parsed — skipping comment: ' + e.message);
+              return;
+            }
+
+            const files = Array.isArray(data.files) ? data.files : [];
+
+            if (files.length === 0) {
+              console.log('No files in analysis output — skipping comment.');
+              return;
+            }
 
-Safety Score: ${data.safety_score}/100
+            const highestRiskFile = files.reduce((max, f) => {
+              return (f.risk_score ?? 0) > (max.risk_score ?? 0) ? f : max;
+            }, files[0] || {});
 
-Top risks:
-${data.top_risks?.map(r => `- ${r}`).join('\n') || '- None'}
+            const riskScore = highestRiskFile.risk_score ?? 0;
+            const safetyScore = 100 - riskScore;
+            const fileName = highestRiskFile.file || 'unknown';
+            const riskDrivers = Array.isArray(highestRiskFile.risk_drivers)
+              ? highestRiskFile.risk_drivers
+              : [];
 
-Prevent this automatically in CI:
+            const driversText = riskDrivers.length > 0
+              ? riskDrivers.map(r => "- " + r).join("\n")
+              : "- None identified";
 
-\`\`\`yaml
-- uses: Camj78/costguardai-action@v1
-\`\`\`
-`;
+            const body =
+              "## CostGuardAI Safety Report\n\n" +
+              "**File:** `" + fileName + "`\n" +
+              "**Safety Score:** " + safetyScore + "/100 (100 - risk score of " + riskScore + ")\n\n" +
+              "**Risk Drivers:**\n" +
+              driversText + "\n\n" +
+              "---\n" +
+              "Add CostGuardAI to your CI pipeline:\n\n" +
+              "```yaml\n" +
+              "- uses: Camj78/costguardai-action@v1\n" +
+              "```";
 
             await github.rest.issues.createComment({
               issue_number: context.issue.number,