ops(q81): the wrapper forwards __lease-capability to mosaic-old (Mos)

Mos amended ruling (2): with no environment location for
MOSAIC_LEASE_VERSION_PROBE_COMMAND, the wrapper sends only
`__lease-capability` to ~/.npm-global/bin/mosaic-old, so the old CLI's
lease gate still gets its answer. Every other subcommand reaches the
pinned worktree; undo removes the forward with the wrapper. update now
rewrites the wrapper, and status flags a wrapper that differs from what
the script writes. Checked live at 21:17:58Z: the probe answered
{"name":"lease-runtime-activation","version":1}, exit 0.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

agents/sage/work/q81/lease-gate-notes.md

@@ -12,3 +12,13 @@
 - Alternative inside files Q81 owns: the new wrapper forwards only `__lease-capability`
   to ~/.npm-global/bin/mosaic-old. Same effect as the env var (the real old CLI answers),
   no env file, removed by undo. Needs Mos's ok, since it differs from the ruling's mechanism.
+
+## Amendment, 2026-10-11T21:17Z (Mos, amending ruling (2))
+
+Mos ruled the env location the original ruling assumed doesn't exist, so the
+wrapper forwards instead. `mosaic __lease-capability` goes to
+~/.npm-global/bin/mosaic-old; every other subcommand goes to the pinned
+worktree. `undo` removes the wrapper and the forward with it. Checked at
+21:17:58Z in a login shell: `mosaic __lease-capability` answered
+{"name":"lease-runtime-activation","version":1} with exit 0, and `mosaic bus
+status` and `mosaic launches list` still answered from the worktree.

agents/sage/work/q81/mosaic-cli.sh

@@ -3,7 +3,8 @@
 #
 #   mosaic-cli.sh install [REF]   rename the npm-global `mosaic` to `mosaic-old`,
 #                                 add a pinned worktree and the wrapper
-#   mosaic-cli.sh update [REF]    move the pinned worktree to REF
+#   mosaic-cli.sh update [REF]    move the pinned worktree to REF and
+#                                 rewrite the wrapper
 #   mosaic-cli.sh undo            remove the wrapper and the worktree, rename
 #                                 `mosaic-old` back to `mosaic`
 #   mosaic-cli.sh status          what is installed, and whether it drifted
@@ -14,6 +15,9 @@
 # checkout, so `mosaic queue` refuses there (the queue runs only in the
 # canonical checkout); queue work stays on scripts/mosaic.
 #
+# The wrapper sends only `__lease-capability` to mosaic-old, so the old
+# CLI's lease gate (activation_version_gate.py) still gets its answer.
+#
 # Writes only: ~/.npm-global/bin/{mosaic,mosaic-old}, the worktree and
 # state directory below, and the canonical checkout's worktree list.
 set -euo pipefail
@@ -55,16 +59,22 @@ deps() {
   echo "node_modules: npm ci done"
 }
 
-write_wrapper() {
-  local tmp
-  tmp="$(mktemp "$BIN/.mosaic.XXXXXX")"
-  cat >"$tmp" <<EOF
+render_wrapper() {
+  cat <<EOF
 #!/usr/bin/env bash
 $MARKER
 # Runs the mosaic-stack CLI pinned in $WT.
-# The estate CLI it replaced is $BIN/mosaic-old.
+# The estate CLI it replaced is $BIN/mosaic-old. Its lease probe still
+# answers there, for old-path launches (Mos, Q81, amending ruling (2)).
+[ "\${1:-}" = __lease-capability ] && exec "$BIN/mosaic-old" "\$@"
 exec "$WT/scripts/mosaic" "\$@"
 EOF
+}
+
+write_wrapper() {
+  local tmp
+  tmp="$(mktemp "$BIN/.mosaic.XXXXXX")"
+  render_wrapper >"$tmp"
   chmod 0755 "$tmp"
   mv -f "$tmp" "$BIN/mosaic"
 }
@@ -91,6 +101,7 @@ cmd_update() {
   [ -z "$(git -C "$WT" status --porcelain --untracked-files=no)" ] || die "$WT has tracked changes; refusing"
   git -C "$WT" checkout -q --detach "$sha"
   deps
+  write_wrapper
   log "update $sha"
   echo "updated: $WT at $sha"
 }
@@ -109,7 +120,9 @@ cmd_undo() {
 
 cmd_status() {
   local bad=0 sha origin
-  if is_wrapper; then echo "wrapper: $BIN/mosaic (marker ok)"
+  if is_wrapper; then
+    if cmp -s "$BIN/mosaic" <(render_wrapper); then echo "wrapper: $BIN/mosaic (marker ok, matches this script)"
+    else echo "DRIFT: wrapper differs from what this script writes; run update"; bad=1; fi
   elif is_old_link "$BIN/mosaic"; then echo "wrapper: none; $BIN/mosaic is the estate symlink"
     [ -e "$WT" ] && { echo "DRIFT: worktree exists but the wrapper is gone (an npm i -g --force?)"; bad=1; }
   else echo "DRIFT: $BIN/mosaic is neither the wrapper nor the estate symlink"; bad=1; fi