docs: clarify GitHub Models availability in AI triage workflow

Add comments explaining that GitHub Models access may not be available in all
environments and that 401 (Unauthorized) errors are expected and handled
gracefully. The workflow will skip AI triage silently but continue processing
the issue through other automation.

.github/workflows/ai-triage.yml

@@ -5,6 +5,11 @@ on:
       - opened
       - edited
 
+# Note: This workflow uses GitHub Models which may not be available
+# in all environments. If GitHub Models API returns 401 or is unavailable,
+# the workflow will skip gracefully and the issue will still be processed
+# by other automation (labeler, etc.)
+
 permissions:
   issues: write
   contents: read
@@ -68,6 +73,10 @@ jobs:
             }
 
             // ── Call GitHub Models ────────────────────────────────────────
+            // Note: GitHub Models access may not be available in all environments.
+            // If the API returns 401 (Unauthorized), it means GitHub Models is not
+            // enabled for this repository or the current token lacks access.
+            // The workflow will gracefully skip AI triage and continue.
             let triage;
             try {
               const res = await fetch(
@@ -120,6 +129,8 @@ jobs:
                 }
               );
 
+              // GitHub Models may return 401 if not available for this repository.
+              // This is expected and not an error — the workflow simply skips AI triage.
               if (!res.ok) {
                 console.log(`GitHub Models returned ${res.status} — skipping AI triage.`);
                 return;