test: temporarily disable tts-gateway mTLS for Mac-side testing

TODO: revert once done - restores plaintext-only gRPC (no client cert
required) so synthesis can be exercised via port-forward + grpcurl
-plaintext from outside the cluster, without extracting cert material.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

manifests/home-services/tts-gateway.yaml

@@ -42,8 +42,10 @@ spec:
               value: "info"
             - name: LOG_FORMAT
               value: "json"
-            - name: TLS_DIR
-              value: /tls
+            # TODO: uncomment to re-enable mTLS - temporarily disabled for
+            # direct grpcurl -plaintext testing from outside the cluster.
+            # - name: TLS_DIR
+            #   value: /tls
           readinessProbe:
             tcpSocket:
               port: 50053