test(marmot-interop): unwrap newer whitenoise-rs groups show shape

Whitenoise-rs ≥ v0.2.x nests the group object one level deeper —
`{"result": {"group": {...}}}` instead of `{"result": {...}}`. The two
metadata-name pollers in tests 07 and 10 still asked for `.result.name`
and silently saw the empty string, so even when wn-side `groups show`
returned the correct new name the polling loops timed out:

    07 metadata rename       fail   B saw name="" not "Interop-02-renamed"
    10 concurrent commits    fail   diverged: A sees "race-from-amethyst", B sees ""

Both queries now also peel a `.group` wrapper when present, leaving the
older bare-`result` shape working too. Re-running the headless harness
flips 07 + 10 from fail → pass; the remaining failures (09, 14, 15) are
unrelated MLS-encryption / Remove-commit issues that need their own fix.

https://claude.ai/code/session_013VYkpz8P1mPh9Ejxy9anhJ

cli/tests/marmot/tests-extras.sh

@@ -89,7 +89,10 @@ test_10_concurrent_commits() {
 
   sleep 10
   local b_name
-  b_name=$(wn_b --json groups show "$mls_gid" 2>/dev/null | jq -r '(.result // .) | .name // empty')
+  # whitenoise-rs ≥ v0.2.x wraps the group payload one level deeper as
+  # `{"result": {"group": {…name…}}}`; the older shape was a bare group
+  # object under `.result`. Accept both.
+  b_name=$(wn_b --json groups show "$mls_gid" 2>/dev/null | jq -r '(.result // .) | (.group // .) | .name // empty')
   local a_name
   a_name=$(amy_field '.name' marmot group show "$gid" 2>/dev/null || echo "")