elp-input.el: replace broken engram_search_json with engram_activate_json
as Layer 1. Layer 2 suppress/filter keeps nodes with non-zero salience/
importance. Reason step extracts patient from top activated node content.
ELP grammar realizes the response via generate().
routes.el: add 'elp' event_type to handle_dharma_recv so the studio can
route ELP requests through dharma.