Fix JSON parsing by sending info messages to stderr

The create-tailnet.sh script now sends informational messages to stderr
so that only valid JSON is sent to stdout. This fixes the jq parsing
error in the workflow where extra text was mixed with JSON output.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: rajsinghtech

tailscale/scripts/create-tailnet.sh

@@ -20,7 +20,7 @@ if ! echo "$TAILNET_NAME" | grep -E '^[a-zA-Z0-9_]+$' > /dev/null; then
     exit 1
 fi
 
-echo "Creating API-only tailnet: $TAILNET_NAME"
+echo "Creating API-only tailnet: $TAILNET_NAME" >&2
 
 RESPONSE=$(curl -s -w "\nHTTP_STATUS:%{http_code}" -X POST https://api.tailscale.com/api/v2/organizations/-/tailnets \
   --header "Authorization: Bearer $ACCESS_TOKEN" \
@@ -36,5 +36,5 @@ if [ "$HTTP_STATUS" != "200" ]; then
     exit 1
 fi
 
-echo "Tailnet created successfully:"
+echo "Tailnet created successfully:" >&2
 echo "$RESPONSE_BODY" | jq .