Fix: set min-integrity to none so agent can read issue content

The gh-aw v0.62.5 DIFC policy blocks untrusted content by default.
Issues are user-submitted (integrity: none), but the agent required
'approved'. Set min-integrity: none to allow reading all issues.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: MackinnonBuck

.github/workflows/issue-classification.lock.yml

@@ -26,6 +26,7 @@ permissions:
 tools:
   github:
     toolsets: [default]
+    min-integrity: none
 safe-outputs:
   staged: true
   add-labels: