The preferences store was loaded once at shell startup, and every save wrote
the whole in-memory copy back. Anything that reached the file after startup --
a hand edit, a script, another shell instance flushing during a session
handoff -- was erased by the next unrelated save. That is how a display scale
set to 1.5 kept coming back as 2: the entry was written, then silently
clobbered, and the catch-all auto rule filled the gap.
Two halves, either alone insufficient. The store now watches its file and
adopts outside writes instead of holding a stale copy over them; and a save
merges with what is on disk rather than overwriting it -- keys this shell has
set win, keys it has never seen survive. A setting changed anywhere now
persists until it is changed again, which is the only behavior a settings
file is entitled to have.
Claude-Session: https://claude.ai/code/session_01Epx9ZC1gwm81K3jm9x9CKh
Gabriel Brown
d865cb74a1