Root cause of 'model+effort switch works on Mac, not on Windows': the
switch APPLIES in-session (the dispatch/apply chain is platform-identical,
verified adversarially) but its persistence never sticks on Windows.
Every tmp+rename atomic write except auth/storage.rs committed with a
bare fs::rename, and Windows MoveFileExW(REPLACE_EXISTING) fails with a
sharing violation whenever AV/search-indexer/cloud-sync transiently holds
the destination open. Consequences: [models].default never persisted
(next launch = original model), the session summary's current model never
persisted (resume = original model), and the models cache went silently
stale (all its write errors were swallowed).
- New kigi_shell_base::util::fs::replace_file — THE commit step for
tmp+rename: plain rename on Unix; on Windows delete-first + two short
backoffs (the pattern auth/storage.rs shipped first), tmp cleaned on
failure, error always returned. Windows branch type-checked against
x86_64-pc-windows-msvc.
- Adopted at every replace site: config.toml (save_config /
atomic_write_string / mcp saves), models cache (plus unique tmp
suffixes and tracing::warn on failure — writes were fully silent),
session storage (summary/current-model, jsonl, plan/signals/
announcement/goal/graph state), auth.json, active-sessions registry,
prompt history, claude/kimi import, campaigns state, goal artifacts.
Directory-move renames (worktree pool, corrupt-file backups) keep
plain rename — their destinations don't pre-exist.
Verified: kigi-shell + kigi-shell-base 5318 tests green, clippy clean,
msvc-target check of the new cfg(windows) code clean.
ZacharyZhang-NY
27d009cb6e