zanmaisnapshotlisted

# snapshot Make a rollback point. Always before risky writes, on demand otherwise. ## Directive A snapshot exists as an entry in the history, written by the script. A conversational claim of having "taken a snapshot in memory" is not a snapshot. Run the script. It is not a copy of the vault. Every file is stored once by its content, so an unchanged file costs nothing on the second snapshot and a changed line costs the line. That is why taking one is never the expensive choice and why nothing has to be cleaned out afterwards. If nothing changed since the last one, none is taken and the script says so. The single config flag `auto_snapshots` in `zanmai/user.md` is the master switch. `zanmai.py snapshot create` reads it every time and exits with `skip: auto_snapshots disabled` when set to `false`, including invocations of this skill. When the user has their own backup discipline they flip it via `zanmai.py snapshot disable` (and `enable` to turn back on). The script is what counts, no separate disable list. ## When to use Four cases, and they share one shape: Zanmai is about to overwrite material that already exists, in a way it cannot undo one file at a time. - Before a distribution update. - Before a bulk repair, one pattern applied across many files. - Before a rename that rewrites links throughout the vault. - Before restoring from an earlier snapshot, since that overwrites the current state. Plus the one case that is not a rule: the user asks for a rollback point i