`kontrol simplify-node --config-profile <profile>` ignores `kontrol.toml` and specified profile

[juliankuners]

kontrol simplify-node --config-profile <profile> ignores kontrol.toml and the specified profile.

This can be reproduced with the kontrol project in this repository: https://github.com/juliankuners/test-simplify-node

[peter941221]

I opened a PR for this: #1154

The root cause was in the TOML dispatch layer, not in simplify-node itself. pyk.parse_toml_args only reads [args.command], so a config file with [prove.*] but no [simplify-node.*] leaves simplify-node with no TOML settings at all.

The patch makes simplify-node, step-node, section-edge, and get-model fall back to prove TOML settings, while still letting command-specific sections override the fallback when present.