User hit 'fatal: not in a git directory' on re-install because:
1. They ran Remove-Item -Force $env:LOCALAPPDATA\hermes -ErrorAction
SilentlyContinue WHILE cd'd inside the install dir. Windows
silently refuses to delete a directory any shell is currently cd'd
inside and leaves the skeleton intact, but the -ErrorAction
SilentlyContinue swallowed every partial-delete failure so they
thought the wipe succeeded.
2. The installer then walked into Install-Repository, saw $InstallDir
still exists with a partial .git stub, my repo-validity probe
returned success (the probe's git rev-parse may have exit-code-zeroed
in a way I didn't expect), and the real git fetch died with three
'fatal: not a git repository' errors.
Two fixes belt-and-braces:
- Main() now cds to $env:USERPROFILE at start if the current shell
is inside $InstallDir. Harmless when the user ran from elsewhere;
critical when they didn't. This alone fixes the user's case.
- Install-Repository's 'is this a valid repo' probe now runs BOTH
git rev-parse --is-inside-work-tree AND git status, resets
$LASTEXITCODE before each to avoid picking up a stale 0, and
requires BOTH to succeed. Also requires rev-parse's output to
match 'true' (not just exit 0) to rule out exit-0-with-empty-output
edge cases.