Merge branch 'feat/p3-editor-coverage' into feat/p3-remote-editor

# Conflicts:
#	CHANGELOG.md
#	CLAUDE.md
#	docs/design/range-reads.md

docs/design/range-reads.md

@@ -9,6 +9,16 @@ change. Progress: M0 and M1 are done, and so is M2 (branch
 `feat/p3-m3-remote`: the `clawhdf5-remote` crate (block cache, HTTP(S),
 object stores) and URLs in `h5rs` (see the M3 status below). M4 (wasm) is
 next. Every count in §1–§2 was
+
+change. Progress: M1, first part (the `Storage` trait and the metadata
+parsers listed in `CHANGELOG.md` under "Range reads, milestone M1") is done;
+group B-tree v2 lookups, dense groups and the facade are not converted yet.
+Later the same day (branch `feat/p3-editor-coverage`) two reader fixes touched
+converted code without changing the plan: object-header continuation chunks
+are followed without recursion (still one bounded `read_at` per chunk), and
+implicit chunk indexes are addressed over the maximum chunk grid (in
+`chunked_read`, an M2 module). The in-place editor (`FileEditor`) keeps
+working on the whole file in memory; it is not part of this design. Every count below was
 taken on `tank` on 2026-09-26 at commit `de2a53f`, with the commands given
 next to it. No timing numbers appear here on purpose: the machine was shared
 with other build jobs when this was written.