row 238: stack-release's sso-config first step carries --instance NAME on a named instance (#1744)

Lands Launchpad's round 3 candidate, manifest 1bf831f3 (4c90099ea on launchpad/row238-r4, base
c515273db), approved by Webby (29956, rev 2717). Three paths: scripts/stack-release.sh, packages/cli/tests/
stack-release.test.mjs and docs/TOOLS.md. It is row 200's follow-up N1. Round 3 only merges docs/TOOLS.md
onto the row 240 landing: the landed blob plus the one hunk at :599. The 3-path patch-id, b9d0bb0ee3c7,
is the same in all three rounds, and stack-release.sh stays 100755.

Evidence: Launchpad's slot run on round 2, 2afbfbb01: stack-release.test.mjs 196/0 (sage-1794). Sage's
combined gate with row 228 on c515273db plus both rows' paths (07:11:30Z to 07:23:34Z): packages/seat 165 pass, 0 fail; packages/cli 640 pass, 0 fail; all ten scripts/test-*.sh 585 pass, 0 fail (out/, run.log). Row 238's mutant, the sso-config first step dropping --instance NAME, was killed (2 fails), survived: none, and stack-release.sh was restored to its blob.
`queue review verify-commit 238` matches the manifest on all 3 paths. Round 1's N1 stays on the #1744
carry list.

scripts/stack-release.sh

@@ -929,12 +929,13 @@ sso_checks() {
     sso_supported || { check_refuse sso-target "$TO's Console does not support --sso"; return 0; }
     local cfg="${MOSAIC_CONFIG:-$HOME/.config/mosaic-dev/config.json}" out id slot path why
     # N4 (webby-0019, sage-1403): a pre-phase-1 loader refuses a console key, so with the key not yet
-    # written and the stack on another copy, the first step is the re-pin without --sso.
-    local first=""
+    # written and the stack on another copy, the first step is the re-pin without --sso. On a named
+    # instance both commands carry --instance NAME (row 238).
+    local first="" inst="${INSTANCE_FLAGS[*]:+ ${INSTANCE_FLAGS[*]}}"
     if ! out="$(node -e "$SSO_JS" -- "$COPIES/$TO" "$cfg" 2>&1)"; then
         out="${out%%$'\n'*}"
         [ "$out" != "there is no console.sso in the system config" ] || [ "$P_COPY" = "$TO" ] ||
-            first="; activate $TO without --sso first, then write console.sso, then run activate $TO --sso"
+            first="; activate $TO$inst without --sso first, then write console.sso, then run activate $TO$inst --sso"
         check_refuse sso-config "$TO's Console would refuse its --sso start: $out$first"
         return 0
     fi