Fix nemotron-super tool_call_parser; auto-clear WireGuard hostname from known_hosts

- hyperstack-vm.toml: set tool_call_parser=llama3_json for nemotron-super so vLLM
  accepts tool_choice requests from opencode; model won't spontaneously call tools
  so the vLLM 0.17.1 token_ids crash in llama3_json won't trigger
- hyperstack.rb: wait_for_ssh now also removes the WireGuard hostname
  (hyperstack.wg1) from known_hosts alongside the IP, preventing
  StrictHostKeyChecking failures across VM recreates

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/snippets/hyperstack/hyperstack.rb b/snippets/hyperstack/hyperstack.rb
index 2ab53c9..f46ce6b 100644
--- a/snippets/hyperstack/hyperstack.rb
+++ b/snippets/hyperstack/hyperstack.rb
@@ -1106,9 +1106,11 @@ module HyperstackVM
     end
 
     def wait_for_ssh(host)
-      # Remove stale host key for this IP — VMs frequently reuse IPs after
-      # delete/recreate, causing StrictHostKeyChecking to reject the new key
+      # Remove stale host keys for both the IP and the WireGuard hostname — VMs
+      # frequently reuse IPs and the same WireGuard alias after delete/recreate,
+      # causing StrictHostKeyChecking to reject the new host key.
       remove_stale_host_key(host)
+      remove_stale_host_key(@config.wireguard_gateway_hostname)
       info "Waiting for SSH on #{host}:#{@config.ssh_port}..."
       with_polling("SSH on #{host}:#{@config.ssh_port}") do
         next nil unless tcp_open?(host, @config.ssh_port)