Backlog 4: #43 and #44 logged 332c1241a11c

     under 100 ms for the mount. Write the design into the hub and

     oxygenflow specs first. A fork of VS Code only if an extension cannot

     do what is needed, decided with Andy.

   `.git` is skipped (oxygen#43), and honour `.gitignore` or offer to import

   it (oxygen#44).

3. - [ ] **Device sign-in** for apps and `oh` (oxygenhub#67): approve a code on

- 2026-10-01 01:20 Flow runs #150 to #153 failed: the Rust build image had no `mimalloc` (jobs build offline from vendored crates). Rebuilt the image, imported it on Earth, pinned it in oxygen, oxygenhub and oxygenflow (oxygenflow#20); runs oxygen #154, oxygenhub #61 and oxygenflow #35 pass. Lesson: watch the run after every push, a dependency change above all.

- 2026-10-01 01:35 **S7 measured, not done.** The first commit of the Linux tree peaks at 2.7 GB (counting allocator; 3.1 GB resident): the walk holds every file's text (1.6 GB, shared with the change's inserts), building the change adds 0.5 GB, and encoding and storing adds 0.5 GB at the peak. Writing the change's encoding an edit at a time instead of through one CBOR value saved only 50 MB, so it was not kept. Under 2 GB needs the text never all in memory: the walk stores each added text file as its text blob as it reads it and keeps only the reference; the builder makes skeleton inserts (lines left out, a `TextRef` beside them, as history-only loads already hold changes); encoding, the commit's re-encoding, history rewrites and adding the change to a state take the skeleton and its texts. Rename detection still reads the contents of added files when files were removed. A day's careful work across objects, snapshot, commit and rewrite: left for a fresh start, with this as the design.