Chi router with all entity CRUD endpoints, promote/demote/use
actions, tag listing. CORS middleware for --dev mode. Graceful
shutdown on SIGINT/SIGTERM. 22 API integration tests via httptest.
Default command delegation: `nib "..."` routes to `nib add`. Capture
bar parses grammar, creates entities. `nib ls` lists with date
grouping, tag filter, 48h default window. Display glyphs for all
entity types.