docs: two-machine sync rule - fetch first, never force-push

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: sturimcode

CLAUDE.md

@@ -41,3 +41,4 @@ Zero-dependency Node CLI + Claude Code Stop hook that auto-titles Claude Code se
 - TDD; tests assert behavior through the real filesystem (temp dirs), never mock internals. Injectable seams for process boundaries only (`runner`, `spawn`, stream, env-var store paths).
 - Comments explain why, not what. Plain engineering register in all user-facing text - no marketing vocabulary.
 - This tool depends on two undocumented Anthropic formats (transcript JSONL, app-store files). Every read is best-effort with a benign failure mode (titles stop applying; protection degrades to heuristics - never corruption, never a crash). Keep new code on that posture, and keep the README honest about it.
+- Two machines develop this repo with GitHub as the only bridge, and nothing syncs on its own. At session start, before touching anything: `git fetch origin`, and if `origin/main` is ahead of the local branch, fast-forward onto it (`git merge --ff-only origin/main`). Never force-push and never rewrite pushed history - prior syncs replayed every commit with new SHAs, which reached the other machine as a forced update and cost a hard reset. If a push is rejected because origin is ahead, pull and rebase the local commits on top of origin instead.