The cached git config runs its `git config` reads through raw
exec.Command calls, outside the pinned git command builder, so they
followed the process working directory. A cache miss on a stale
instance — one still in use by a refresh that crossed a repo switch —
would therefore read the new repo's local config while computing data
for the old one. Give the cache a directory, set once by NewGitCommand
right after it determines the repo paths (the object is created fresh
for every repo switch, so no cross-repo cache invalidation is needed),
and run every config command there.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This allows changing git config values while lazygit is running (e.g. in a
different terminal tab, or even in lazygit's ":" shell prompt), and have them
take effect immediately, while still getting some benefit from caching them
while lazygit is in the foreground.
