feat(admin): live redis kill-switch on tunnel actions, sortable columns + CSV export + bulk actions, Node 24 LTS

WS1: pin all Docker stages to node:24.16.0-alpine; add engines node>=20.
WS2: lib/redis.ts gains TTL-backed redisSet, redisDel, setTunnelActive (writes tunnel:active:<sub>=1/0 EX 30, TUNNEL_ACTIVE_TTL override, no-op without REDIS_URL); wired into tunnel active/delete/reassign routes.
WS3: sortable columns, CSV export routes (token excluded), and bulk actions (self-account guard) across users/tunnels/audit admin tables.

app/admin/audit/audit-table.tsx

@@ -3,6 +3,7 @@
 import { useCallback, useEffect, useRef, useState } from 'react';
 import { formatDate } from '@/lib/format';
 import type { AuditItem } from '@/lib/admin/list';
+import { SortHeader, downloadUrl, type SortOrder } from '../table-ui';
 
 const PER_PAGE = 50;
 
@@ -18,20 +19,28 @@ export function AuditTable({
   const [page, setPage] = useState(1);
   const [action, setAction] = useState('');
   const [targetType, setTargetType] = useState('');
+  const [sort, setSort] = useState('created_at');
+  const [order, setOrder] = useState<SortOrder>('desc');
   const [loading, setLoading] = useState(false);
   const [error, setError] = useState<string | null>(null);
 
+  const queryParams = useCallback(() => {
+    const params = new URLSearchParams({
+      page: String(page),
+      perPage: String(PER_PAGE),
+      sort,
+      order,
+    });
+    if (action.trim()) params.set('action', action.trim());
+    if (targetType.trim()) params.set('target_type', targetType.trim());
+    return params;
+  }, [page, action, targetType, sort, order]);
+
   const load = useCallback(async () => {
     setLoading(true);
     setError(null);
     try {
-      const params = new URLSearchParams({
-        page: String(page),
-        perPage: String(PER_PAGE),
-      });
-      if (action.trim()) params.set('action', action.trim());
-      if (targetType.trim()) params.set('target_type', targetType.trim());
-      const res = await fetch(`/api/admin/audit?${params.toString()}`, {
+      const res = await fetch(`/api/admin/audit?${queryParams().toString()}`, {
         credentials: 'same-origin',
       });
       if (!res.ok) {
@@ -49,7 +58,7 @@ export function AuditTable({
     } finally {
       setLoading(false);
     }
-  }, [page, action, targetType]);
+  }, [queryParams]);
 
   // First page is server-rendered; skip the on-mount fetch to avoid racing the
   // SSR session-cookie refresh (which intermittently 401'd).
@@ -63,6 +72,23 @@ export function AuditTable({
     return () => clearTimeout(t);
   }, [load]);
 
+  function onSort(col: string) {
+    setPage(1);
+    if (col === sort) {
+      setOrder((o) => (o === 'asc' ? 'desc' : 'asc'));
+    } else {
+      setSort(col);
+      setOrder('asc');
+    }
+  }
+
+  function exportCsv() {
+    const params = new URLSearchParams({ sort, order });
+    if (action.trim()) params.set('action', action.trim());
+    if (targetType.trim()) params.set('target_type', targetType.trim());
+    downloadUrl(`/api/admin/audit/export?${params.toString()}`);
+  }
+
   const totalPages = Math.max(1, Math.ceil(total / PER_PAGE));
 
   return (
@@ -93,6 +119,15 @@ export function AuditTable({
         <button className="secondary btn-sm" type="button" onClick={load}>
           Refresh
         </button>
+        <div className="toolbar-actions">
+          <button
+            className="secondary btn-sm"
+            type="button"
+            onClick={exportCsv}
+          >
+            Export CSV
+          </button>
+        </div>
       </div>
 
       {error && <p className="error">{error}</p>}
@@ -106,9 +141,27 @@ export function AuditTable({
           <table className="admin-table">
             <thead>
               <tr>
-                <th>When</th>
-                <th>Actor</th>
-                <th>Action</th>
+                <SortHeader
+                  label="When"
+                  col="created_at"
+                  sort={sort}
+                  order={order}
+                  onSort={onSort}
+                />
+                <SortHeader
+                  label="Actor"
+                  col="actor_email"
+                  sort={sort}
+                  order={order}
+                  onSort={onSort}
+                />
+                <SortHeader
+                  label="Action"
+                  col="action"
+                  sort={sort}
+                  order={order}
+                  onSort={onSort}
+                />
                 <th>Target</th>
                 <th>Details</th>
               </tr>