feat(integrations): поле «Прокси» в форме интеграции (frontend)

- model.ts: config.proxyUrl в типе Integration.
- IntegrationForm.tsx: стейт proxyUrl, поле «Прокси» (placeholder
  http://user:pass@host:port) для всех провайдеров кроме WEB (виджет клиентский),
  proxyUrl в payload create/update.

apps/internal-ui/src/features/integrations/IntegrationForm.tsx

@@ -18,6 +18,7 @@ export function IntegrationForm({ initial, onClose, onSaved }: { initial: Integr
   const [secret, setSecret] = useState("");
   const [baseUrl, setBaseUrl] = useState(initial?.config.baseUrl ?? "");
   const [defaultModel, setDefaultModel] = useState(initial?.config.defaultModel ?? "");
+  const [proxyUrl, setProxyUrl] = useState(initial?.config.proxyUrl ?? "");
   const [channelId, setChannelId] = useState(initial?.channel ? String(initial.channel.id) : "");
   const [channels, setChannels] = useState<ChannelOption[]>([]);
   const [submitting, setSubmitting] = useState(false);
@@ -49,7 +50,7 @@ export function IntegrationForm({ initial, onClose, onSaved }: { initial: Integr
     if (!ready) return;
     setSubmitting(true);
     setError(null);
-    const config = { baseUrl: baseUrl.trim(), defaultModel: defaultModel.trim() };
+    const config = { baseUrl: baseUrl.trim(), defaultModel: defaultModel.trim(), proxyUrl: proxyUrl.trim() };
     const channel = isMessenger ? { channelId: channelId ? Number(channelId) : null } : {};
     try {
       if (isEdit) {
@@ -90,6 +91,9 @@ export function IntegrationForm({ initial, onClose, onSaved }: { initial: Integr
           />
         )}
         <FormField label="Base URL" value={baseUrl} onChange={setBaseUrl} placeholder={meta.defaultBaseUrl || "—"} />
+        {!isWeb && (
+          <FormField label="Прокси" value={proxyUrl} onChange={setProxyUrl} placeholder="http://user:pass@host:port — пусто, если без прокси" />
+        )}
         {meta.hasModel && (
           <FormField label="Модель по умолчанию" value={defaultModel} onChange={setDefaultModel} placeholder="anthropic/claude-sonnet-4.6" />
         )}

apps/internal-ui/src/features/integrations/model.ts

@@ -10,7 +10,7 @@ export type Integration = {
   provider: IntegrationProvider;
   name: string;
   hasSecret: boolean;
-  config: { baseUrl: string; defaultModel: string; botId: string; botUsername: string; botName: string };
+  config: { baseUrl: string; defaultModel: string; proxyUrl: string; botId: string; botUsername: string; botName: string };
   channel: { id: number; code: string; name: string } | null;
   status: IntegrationStatus;
   lastCheckedAt: string | null;