feat(admin-ui): members panel, invite links, audit tab and role-aware console

- New MembersPanel: role switching, add/remove members, invite-link
  generation with copy/revoke, pending invite list
- New Audit tab (AuditLog.vue) with group filter
- Role-aware UI: viewer hides route/group edit actions (RouteCard readonly),
  owner-only controls, role badge + member count on group cards
- GroupEditor: members managed via panel, owners field super-admin only
- en/zh i18n and CSS for the new panels

admin/assets/css/main.css

@@ -1130,6 +1130,135 @@ main {
   white-space: pre-wrap;
 }
 
+/* ---- Members panel ---- */
+.members-panel {
+  margin-top: 28px;
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  padding: 18px 20px;
+}
+
+.panel-head {
+  display: flex;
+  align-items: baseline;
+  gap: 10px;
+  flex-wrap: wrap;
+  margin-bottom: 12px;
+}
+
+.panel-head h3 {
+  font-size: 14px;
+  letter-spacing: 0.3px;
+}
+
+.members-panel h4 {
+  font-size: 12px;
+  margin: 14px 0 8px;
+}
+
+.member-list {
+  list-style: none;
+  margin: 0 0 12px;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.member-row,
+.invite-row {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  flex-wrap: wrap;
+  padding: 8px 12px;
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: var(--radius-sm);
+}
+
+.member-login {
+  font-weight: 600;
+  font-size: 13px;
+  flex: 1;
+  min-width: 120px;
+}
+
+.role-pill {
+  font-size: 11px;
+  font-weight: 700;
+  border-radius: 999px;
+  padding: 2px 10px;
+  letter-spacing: 0.5px;
+  text-transform: uppercase;
+}
+
+.role-pill.owner {
+  color: var(--accent);
+  background: var(--accent-dim, rgba(88, 101, 242, 0.12));
+}
+
+.role-pill.admin {
+  color: var(--ok);
+  background: var(--ok-dim);
+}
+
+.role-pill.viewer {
+  color: var(--faint);
+  background: var(--surface);
+  border: 1px solid var(--border);
+}
+
+.member-add,
+.invite-create {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex-wrap: wrap;
+}
+
+.text-input {
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  color: var(--text);
+  font-size: 13px;
+  padding: 6px 10px;
+  min-width: 200px;
+  outline: none;
+}
+
+.text-input:focus {
+  border-color: var(--accent);
+}
+
+.invite-box {
+  margin-top: 14px;
+  border-top: 1px dashed var(--border);
+  padding-top: 6px;
+}
+
+.invite-list {
+  list-style: none;
+  margin: 10px 0 0;
+  padding: 0;
+  display: flex;
+  flex-direction: column;
+  gap: 8px;
+}
+
+.invite-token {
+  font-family: var(--mono);
+  font-size: 12px;
+  color: var(--muted);
+}
+
+.invite-exp {
+  font-size: 12px;
+  color: var(--faint);
+}
+
 @media (max-width: 720px) {
   .filter-row {
     grid-template-columns: 100px 1fr auto;