- add tree shell runtime artifact contracts and page/filetree/picker runtime reducers
- sink tree.subtree.move write operation through Rust and formalize command event plans
- harden file tree search projection contract and route thin-proxy boundaries
- record completed harness tasks and move design docs into process/done
- add generic mnote-web query transport and bridge routes for workspace/request/trace
- route sidebar compat traffic through mnote-web and tighten fixture fallback to dev/test
- unify sidebar/page tree/file tree/picker consumers on page_tree projection
- sync phase3/phase4 checklist, breakdown docs, and harness progress state