feat: add a subroutine to load_config to make unrecognized gestures as REST

REST would better absorb unrecognized gestures to avoid unintended gesture triggers.

Start by locating the load_config entry point and inspect how unrecognized gestures are currently handled. Determine where REST is represented as a gesture value and confirm that unknown gestures should resolve to REST rather than trigger another action. Done means this fallback behavior works without changing recognized gestures; no test file is named in the issue.

Written by the indexing model from the issue text.