Move member environment control out of the pane-creation env overlay
(defeated by any file the login shell sources) into a per-spawn ZDOTDIR
directory whose .zlogin runs LAST, after the operator's whole chain, and
blanks every exported variable not on an allow-list DERIVED from what the
launcher itself injects (profiles' tokenEnv/gitTokenEnv/gitHostEnv/env
keys + an infrastructure set) — never hand-typed.
- memberCredentials.policy: allow-list (deny-by-default/deny-list stay
default and unchanged); known:/allow: become reporting only under it.
- memberCredentials.sshAuthSock knob, blocked by default; allowing it is
an explicit decision (operator ssh-agent handle).
- Non-zsh login shell: loud WARN, protection off, fallback to the old
enumerated-name overlay.
- Scrub writes an 'allowed N of M' denominator report, read at teardown;
credential-shaped blanked names go to WARN (names only, never values).
- Equality test against a real login zsh from a clean parent: surviving
non-empty exports EQUAL baseline ∩ derived allow-list.
Dai Ha