test: move re-add-after-remove regression to Quartz MlsGroup test

The bug (re-added user rejoins without a usable own_leaf, so they
can neither decrypt new group messages nor send) reproduces entirely
with two in-process MlsGroup instances — no relay or second Nostr
client needed. A pure Quartz unit test runs in seconds and catches
the regression deterministically, where the bash interop version
depended on whitenoise-rs, wnd daemons and a local relay.

- quartz: add MlsGroupLifecycleTest.testReaddAfterRemove_RejoinerCanEncryptAndDecrypt
  covering create → add → round-trip → remove → re-add with a fresh
  KeyPackage → round-trip again, asserting leafIndex and both
  encrypt/decrypt directions on the rejoined instance.
- interop: drop test_17_readd_after_remove from the headless suite and
  its registration, since the unit test supersedes it.

https://claude.ai/code/session_01JaeqZwVNLKvUUvXWRzPmRP

tools/marmot-interop/headless/tests-manage.sh

@@ -155,95 +155,6 @@ test_08_admin_promote_demote() {
   fi
 }
 
-test_17_readd_after_remove() {
-  banner "Test 17 — Re-add after remove restores B's leaf"
-  local id="17 re-add after remove"
-
-  # Scenario reported on the info screen: A creates a group, adds B,
-  # removes B, then adds B again. Before the fix B rejoined without a
-  # usable own_leaf, so B could see metadata but could neither decrypt
-  # new posts nor sign messages. This test catches that regression by
-  # driving a full round-trip (A→B and B→A) after the re-add.
-
-  local out gid mls_gid
-  out=$(amy_json marmot group create --name "Interop-17-readd") || {
-    record_result "$id" fail "amy create failed"; return
-  }
-  gid=$(printf '%s' "$out" | jq -r '.group_id')
-  mls_gid=$(printf '%s' "$out" | jq -r '.mls_group_id')
-  [[ -n "$gid" && -n "$mls_gid" ]] || {
-    record_result "$id" fail "missing ids from create"; return
-  }
-
-  # A adds B.
-  amy_json marmot group add "$gid" "$B_NPUB" >/dev/null || {
-    record_result "$id" fail "initial add B failed"; return
-  }
-  wait_for_invite B 60 >/dev/null || {
-    record_result "$id" fail "B never received first invite"; return
-  }
-  wn_b groups accept "$mls_gid" >/dev/null 2>&1 || true
-
-  # Confirm the baseline works: A → B and B → A both deliver.
-  amy_json marmot message send "$gid" "pre-remove hello" >/dev/null || {
-    record_result "$id" fail "A send before remove failed"; return
-  }
-  wait_for_message B "$mls_gid" "pre-remove hello" 90 || {
-    record_result "$id" fail "B missed pre-remove hello"; return
-  }
-  wn_b messages send "$mls_gid" "pre-remove pong" >/dev/null 2>&1 || true
-  amy_json marmot await message "$gid" --match "pre-remove pong" --timeout 60 >/dev/null || {
-    record_result "$id" fail "A missed B's pre-remove pong"; return
-  }
-
-  # A removes B.
-  amy_json marmot group remove "$gid" "$B_NPUB" >/dev/null || {
-    record_result "$id" fail "remove B failed"; return
-  }
-  # Let the Remove commit propagate to B's wnd.
-  local deadline=$(( $(date +%s) + 120 )) removed=0
-  while [[ $(date +%s) -lt $deadline ]]; do
-    if ! wn_b --json groups members "$mls_gid" 2>/dev/null \
-         | jq -e --arg p "$B_HEX" '(.result // .) | .[]? | select((.pubkey // .public_key) == $p)' \
-         >/dev/null 2>&1; then
-      removed=1; break
-    fi
-    sleep 3
-  done
-  [[ "$removed" -eq 1 ]] || warn "B still appears in members after remove — continuing"
-
-  # B republishes its KP so the next add can find a fresh one.
-  wn_b keys publish >/dev/null 2>&1 || true
-  sleep 3
-
-  # A re-adds B.
-  amy_json marmot group add "$gid" "$B_NPUB" >/dev/null || {
-    record_result "$id" fail "re-add B failed"; return
-  }
-  wait_for_invite B 60 >/dev/null || {
-    record_result "$id" fail "B never received second invite"; return
-  }
-  wn_b groups accept "$mls_gid" >/dev/null 2>&1 || true
-
-  # Regression probes: after re-add B must have a usable leaf again.
-  # (1) A→B: proves B can decrypt new group messages.
-  amy_json marmot message send "$gid" "post-readd hello" >/dev/null || {
-    record_result "$id" fail "A send after re-add failed"; return
-  }
-  wait_for_message B "$mls_gid" "post-readd hello" 120 || {
-    record_result "$id" fail "B didn't decrypt post-readd message (missing own_leaf?)"; return
-  }
-  # (2) B→A: proves B can still sign/commit — the exact breakage reported.
-  wn_b messages send "$mls_gid" "post-readd pong" >/dev/null 2>&1 || {
-    record_result "$id" fail "B send after re-add failed (likely no leaf)"; return
-  }
-  if amy_json marmot await message "$gid" --match "post-readd pong" --timeout 120 >/dev/null; then
-    record_result "$id" pass
-  else
-    record_result "$id" fail "A never saw B's post-readd pong (B couldn't type)"
-  fi
-}
-
 test_11_leave_group() {
   banner "Test 11 — Leave group"
   local id="11 leave group"

tools/marmot-interop/marmot-interop-headless.sh

@@ -123,4 +123,3 @@ test_13_keypackage_rotation
 test_14_wn_removes_a
 test_15_wn_member_leaves
 test_16_wn_keypackage_rotation
-test_17_readd_after_remove