Redact credentials on the way into a stored chat

A stored transcript is replayed into a later prompt when reopened, so a key typed while
changing a setting would be handed back to the model on every subsequent turn.

Plugin/unraid/api/ai.php

@@ -386,8 +386,11 @@ if ($action === 'ask') {
          . ' >/dev/null 2>&1 </dev/null &';
     $out = []; $rc = 0;
     exec($cmd, $out, $rc);
+    // Redacted before it is logged, for the same reason the stored transcript is: asking the
+    // assistant to set a credential means typing one, and ai.log is neither 0600 nor pruned.
     vv_ai_log(sprintf('ask token=%s rc=%d profile=%s kind=%s q=%s',
-        substr($token, 0, 12), $rc, $profile, $kind ?: '-', mb_substr($question, 0, 80)));
+        substr($token, 0, 12), $rc, $profile, $kind ?: '-',
+        mb_substr(vv_ai_redact($question), 0, 80)));
 
     echo json_encode(['ok' => true, 'token' => $token]);
     exit;