`uv run ga tui2` uses system Python instead of .venv Python

[dougen]

Problem

When running uv run ga tui2 (or any frontend command like gui, cli, hub, tui), the subprocess launches using "python" which resolves to the system Python on PATH, not the .venv Python.

Root Cause

In ga_cli/cli.py, the COMMANDS dict uses "python" as the executable:

"tui2": {
    "cmd": ["python", "{FRONTENDS}/tuiapp_v2.py"],
},

The launch_frontend() function passes this directly to subprocess.Popen without resolving to the current Python (sys.executable).

Fix

Added a check in launch_frontend() to replace "python" with sys.executable:

# Use .venv Python instead of system PATH python
if full_cmd and full_cmd[0] == "python":
    full_cmd[0] = sys.executable

This way all commands (tui2, gui, cli, hub, etc.) will use the same Python that uv run is using (which is the .venv Python).