docs: clean up research notes, add production backlog and working docs

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Vgmzx8VTTTmCskSpQtsLTr

docs/working/backlog.md

@@ -4,6 +4,16 @@ Ideas and improvements not yet planned or scheduled.
 
 ---
 
+## Production — remaining items
+
+- [ ] Set `twig.cache: true` in `user/config/system.yaml` on the server (do not commit — breaks local dev)
+- [ ] Smoke test: submit one post via `/post`, confirm entry appears in dailies immediately (verifies cache-on-save with twig cache on)
+- [ ] Confirm `/post` requires login — unauthenticated visitors must not be able to post
+- [ ] Register at carto.com and review terms for production traffic
+- [ ] Japan & Korea 2026 trip page: set `date_start`, add `cover_image`, upload GPX route file(s)
+
+---
+
 ## GPX Manager (`/gpx-manager`)
 
 - [ ] **Polish the UI** — the current design is functional but bare; align with the Field Notes aesthetic, add better empty states, drag-and-drop upload area