ACI-063: What a Worktree Isolates

Thesis

When discipline on one shared tree keeps failing, isolate the nodes that contend by worktree, not by branch, and keep the board on the shared ref. A worktree isolates source and not state: the database, the publish path, generated files and the board stay shared, their clashes go silent, and instruments that measure within one tree stop seeing another tree move, so the duty to announce grows stronger.

Story

By late July 2026 Lamplight's fleet had a rule for each way its one working tree had bitten, and the rules kept failing. The interface node's scoped commit of an append to a peer's inbox carried that peer's uncommitted clear of the same file, 11 insertions against 129 deletions (Lamplight@31ce5ddc0, 2026-07-26). The next day the control node ran git stash push --keep-index mid-pipeline and took 17 files, a peer's live board and mix.lock among them, when the read-only git show HEAD:<path> in the same command had already answered its question (Lamplight@3e8e15c56, 2026-07-27). A day later the validation node's stash swept two peers' live files, and it wrote "never git stash in the shared repo" on its board (Lamplight@b8028dd4f, 2026-07-28).