Readable copies of every piece, in a folder you choose

Plan for Voice Lab spec §8.4, which was deferred on 2026-09-27 and never built. Source: .claude/plans/writing-backup-folder.md.

Decided today: readable Markdown files only, with no database copy. Each file updates about 5 seconds after typing stops, and on quit or project switch. The 3 latest minted versions of each piece are kept beside it. At setup you pick the folder, starting in ~/Documents/Atticus.

What the folder looks like

Atticus/
  README.txt
  The Couple Poem — 1a2b3c4d.md
  Letter to General Wortham — 9f8e7d6c.md
  versions/
    The Couple Poem — 1a2b3c4d/
      v7.md  v8.md  v9.md

File names are the title plus the first 8 characters of the project ID, so two "Untitled letter" projects never collide. Renaming a project renames its file.
Atticus never deletes a piece's file, even when the project is trashed. Pruning removes only minted versions beyond the latest 3.
Every write is atomic, so a crash never leaves a half-written file.

What gets built

Folder access

A bookmarks entitlement for the sandboxed Release build, plus a folder picker that saves a security-scoped bookmark, so the permission survives relaunches.
Folder problems (moved, deleted, not writable) show up in Settings. Editing is never blocked.

Writing the copies

A writer that turns a project into Markdown, debounced per project, with an immediate flush on project switch and quit.
Hooks into every path that changes a piece's text: typing, generated drafts, applied revisions, restores.
Version files on every mint, pruned to 3. Files are renamed when titles change.

Setup and Settings

A "Keep a copy of your writing" step in first-launch setup, offered once to existing writers with no folder set (including you).
A Backups section in Settings with the folder, Change…, Back up everything now, Turn off, and the last successful write.
Choosing a folder writes every existing project into it immediately.

Tests

Rendering, naming, renames, atomic writes, version pruning, never deleting on trash, debounce behavior, and a missing folder.

Final review

Pros

The copies open in any editor, which covers exactly the Aug 14 failure: a store that won't open, or is gone.
If Documents syncs to iCloud Drive, the copies leave the machine with no extra work.
The copies are independent of the store backups, so either one can fail without the other.

Cons and limits

Only text is copied. Critiques, conversations and Voice Lab stay in the store and its backups.
The last few seconds of typing before a hard crash can be missing from the copy. The store still has them.
Moving the folder makes the bookmark stale. Atticus notices and asks you to pick it again.

Edge cases

Titles containing / or : are sanitized, and a title that's all punctuation becomes "Untitled".
A multi-prompt project is written as one file, with a heading per prompt.
If both Macs write to the same synced folder, files won't collide, because each machine's projects have different IDs.

Worth considering

A "Reveal in Finder" button on each Library item.
Including the latest critique summary in each file.

Confidence 82/100 The main risk is missing a code path that changes a piece's text. Tests cover the writer, and the verification steps cover the hooks.