Store each tool's override under its own key (app.tools.<name>) instead of
one map, so the settings panel can bind a plain text field per tool.
loadSupporterBinaries reads the per-tool keys plus a first-run marker and
keeps an explicit path; redetectSupporterBinaries backs the Re-detect
action. The resolver itself is unchanged.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>