writeAtomic renamed the temporary file over the target without syncing
either: on ext4 with delayed allocation a power cut just after a save
could leave a zero-length script, the exact failure autosave exists to
prevent. Sync the temp file before the rename and the directory after
it. While here, keep an existing file's permissions instead of forcing
0o644, and resolve symlinks first so saving through a link replaces
the file it points to, not the link itself (Dropbox/dotfile setups).
SetDirty runs on a Wails call goroutine while the GTK close handler
reads the flag, with no synchronisation: an edit landing while a save
finished could make the close confirmation unreliable. The spellMu
comment already documents the goroutine-per-call convention; the flag
that guards against losing work deserves the same care.
Kharec