A running local model launches without a default agent
The launch button on a running local model did nothing when no default agent was chosen. A change merged into quattro picks pi, or OpenCode when pi is not installed, before it checks for a default, and the live panel was not clicked.
The error went to the error stream, so the click looked dead. A local model opens in pi, or in OpenCode when pi is not installed, because only those two take a launch-time overlay.
A launch without `--local` still asks for a default. The test covers the launcher path the button runs, and the live panel was not clicked.