feat(config): add [reasoning_only] section for retry count and custom…

[Gabriel-Degret]

Summary

Add a [reasoning_only] config section to make the reasoning-only retry behavior user-configurable.

Before: MAX_REASONING_ONLY_REPROMPTS = 2 was hardcoded. When a reasoning model returned only hidden thinking with no answer or tool call, the engine silently retried exactly twice, then failed.

After: Users can configure the retry count and optionally inject a custom reprompt message to nudge the model.

[reasoning_only]
# Maximum number of automatic re-requests (default: 2). Set to 0 to disable.
max_reprompts = 2

# Optional message sent as a user turn before each retry.
reprompt_message = "So, what's up ? Keep running !"

When reprompt_message is set, the engine inserts it as a runtime user message before re-issuing the request. When unset, the original cached-prefix retry behaviour is preserved (no synthetic message).

Testing

• cargo fmt --all -- --check — clean
• cargo clippy --workspace --all-targets --all-features --locked — warning-free under the CI allow list
• cargo test --workspace --all-features --locked — passes, including 8 existing reasoning_only tests and 1 new config test

Checklist

• Updated docs or comments as needed (docs/CONFIGURATION.md)
• Added or updated tests where relevant (crates/tui/src/config/tests.rs)
• Verified TUI behavior manually if UI changes — no UI changes
• Harvested/co-authored credit uses a GitHub numeric noreply address

[github-actions]

Thanks @Gabriel-Degret for taking the time to contribute.

This repository is observing a maintainer-managed PR intake gate in dry-run mode, so this pull request is staying open. This note helps maintainers prepare the allowlist before any enforcement is considered.

Please read CONTRIBUTING.md for the expected contribution shape. A maintainer can grant recurring PR access by commenting /lgtm on a pull request.