The setup wizard now auto-detects the npx/npx.cmd path via
`which npx` (Unix) or `where npx.cmd` (Windows) and writes it
to [browser].node_path in config.toml.
Changes:
- detect_npx_path(): cross-platform detection using which/where
- SerializedConfig now includes optional [browser] section
- Flat config parser (main.rs) handles [browser] section
- browser: BrowserSection threaded through AgentConfig everywhere
- init_browser() accepts node_path parameter with proper fallback
Tara Menon
cc0ff65e89