Closes the second #97208 atom (qingchuan-x): after a Windows hand-off child refused the
dependency sync (Desktop backend held the venv), the next `hermes update` found git current,
passed the core-import probe — the old release imports fine — and printed
"✓ Already up to date!" while the installed distribution still read hermes-agent 0.20.6
against a 0.21.2 checkout with lagging pins.
`_venv_dependency_set_stale` asks the venv's own interpreter for the installed hermes-agent
version and compares it with pyproject's; a mismatch on the current-checkout path takes
the same repair route as an unhealthy venv. Unknown states (no venv, not installed as a
distribution, probe failure) are never stale, so dev checkouts are untouched.
44945d224c