Say what an upgrade does not reach, and what to run about it

[MongLong0214]

Toward #693 — the half that does not require touching the install path again.

An upgrade updates the CLI and reaches neither:

• hooks already installed in a repository — hooks install records the exact
  bundle it ran from, pinning that repository to one release
• sessions already running — a host loads its runtime once and keeps it

Both show up in doctor, and neither was written down anywhere. A user meeting
those warnings had no way to know they were expected rather than broken.

Why the version is in the recorded path

The obvious repair is wrong, and it was tried rather than reasoned about:
#694 recorded the bin wrapper instead, and hooks then failed under the
restricted PATH a hook actually runs in —

outcome: the hook exited 1 under the restricted PATH —
         commitlore: cannot find the CLI this hook was installed with.

The recorded path exists to be independent of PATH, and commitlore.node is
recorded beside it because a hook runs where PATH may carry no node. A shell
wrapper undoes both. Three local reproductions passed before CI caught it,
because my PATH had node in it.

A version-free path that keeps those properties needs a stable directory the
installer maintains — no such directory exists today, and creating one touches
install.sh, uninstall, and Windows symlink behaviour. That stays in #693.

Why documentation rather than the fix

Six defects came out of the install and distribution path today, one of them mine
from an hour ago. v1.0.1 just shipped and its four controls all inverted. There
is no user-facing reason to reopen that path tonight, and the limit is real
enough to be worth stating either way — the installer genuinely cannot know which
repositories have hooks.

Documentation only; no code, no artifact change.

[github-actions]

CommitLore — record lint

Trailers: clean — 1 commit in origin/main..55e6dc7b50bd7bc0936b0d3422ecf7f2c1fe42f7
Active constraints: not read — commitlore: git log --follow accepts exactly one pathspec, so renames are not followed for 2 paths; query one path at a time to follow its rename chain (2 changed paths)

_{Trailer violations fail this check. Active constraints are informational — they are what the repository already decided, not a verdict on this PR.}