* feat(files): guarded file writes that refuse to overwrite a changed file
Adds an optional disk precondition to file writes: the writer compares the file
on disk with an expected signature inside the write, serialized per file (path
then inode), and refuses with a typed changed/missing result instead of writing.
Remote hosts serve it as files.writeIfUnchanged behind a capability; older
hosts get a client-side compare that fails closed, pinned to the probed runtime
and connection. Undo of a delete and the MCP starter config use it to write only
into a missing or identical file. Groundwork for guarding editor saves.
* fix(files): pin guarded writes on the sending socket; keep refused undo; narrow not-found and pinning
* fix(files): pin a guarded save to one pairing; keep only refused undo steps
* fix(files): ENOENT by code only; resolve symlink chains fully; pin lost-reply recovery to the save's pairing
Neil
OrcaWinandBrennan Benson