Initial commit: thbd-portal, duplicated from elmi-portal

Rebranded for Thunderbird Portal (THBD): numbering prefix EL->TH, all
"ELMI"/"ЭЛМИ" UI strings genericized, ELMI's real contract templates and
company legal/bank details removed (not applicable to this company), fresh
VAPID keypair and encryption key, fresh single-migration schema history.
Same architecture as elmi-portal: Web Push notifications, unread-chat app
badge, cookie-session auth.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Gh2UXUQUVBWroWEnn1FLFG

src/app/(admin)/settings/counterparties/toolbar.tsx

@@ -0,0 +1,18 @@
+"use client";
+
+import { useState } from "react";
+import { Plus } from "lucide-react";
+import { NewCounterpartyModal } from "./new-counterparty-modal";
+
+export function CounterpartiesToolbar() {
+  const [open, setOpen] = useState(false);
+  return (
+    <>
+      <button className="btn btn-primary" onClick={() => setOpen(true)}>
+        <Plus size={16} />
+        Новый контрагент
+      </button>
+      <NewCounterpartyModal open={open} onClose={() => setOpen(false)} />
+    </>
+  );
+}