feat(proxy): add outbound HTTP proxy support for OAuth + provider requests

- Patch Node fetch via undici ProxyAgent when HTTP_PROXY/HTTPS_PROXY/ALL_PROXY is set
- Ensure proxy patch is loaded for both chat pipeline and OAuth token exchange
- Add Dashboard Settings → Network to edit outbound proxy and apply immediately
- Persist outbound proxy settings in local db and initialize on server startup
- Move proxy helpers to src/lib/network/ for better structure
- Rename src/proxy.js → src/dashboardGuard.js to avoid naming confusion
- Re-apply proxy env after DB import
- Fix: close old dispatcher on proxy URL change to prevent connection pool leak
- Fix: idempotency guard to avoid patching globalThis.fetch multiple times

Made-with: Cursor

src/lib/network/outboundProxy.js

@@ -0,0 +1,68 @@
+function normalizeString(value) {
+  if (value === undefined || value === null) return "";
+  return String(value).trim();
+}
+
+export function applyOutboundProxyEnv(
+  { outboundProxyEnabled, outboundProxyUrl, outboundNoProxy } = {}
+) {
+  if (typeof process === "undefined" || !process.env) return;
+  const enabled = Boolean(outboundProxyEnabled);
+  const proxyUrl = normalizeString(outboundProxyUrl);
+  const noProxy = normalizeString(outboundNoProxy);
+
+  // If disabled, only clear env vars we previously managed.
+  if (!enabled) {
+    if (process.env.NINE_ROUTER_PROXY_MANAGED === "1") {
+      delete process.env.HTTP_PROXY;
+      delete process.env.HTTPS_PROXY;
+      delete process.env.ALL_PROXY;
+      delete process.env.NO_PROXY;
+      delete process.env.NINE_ROUTER_PROXY_MANAGED;
+      delete process.env.NINE_ROUTER_PROXY_URL;
+      delete process.env.NINE_ROUTER_NO_PROXY;
+    }
+    return;
+  }
+
+  // When enabled:
+  // - If values are provided, write them and mark as managed
+  // - If values are empty, do not touch externally-provided env,
+  //   but do clear values we previously managed.
+  const wasManaged = process.env.NINE_ROUTER_PROXY_MANAGED === "1";
+  let managed = false;
+
+  if (wasManaged) {
+    if (!proxyUrl) {
+      delete process.env.HTTP_PROXY;
+      delete process.env.HTTPS_PROXY;
+      delete process.env.ALL_PROXY;
+      delete process.env.NINE_ROUTER_PROXY_URL;
+    }
+    if (!noProxy) {
+      delete process.env.NO_PROXY;
+      delete process.env.NINE_ROUTER_NO_PROXY;
+    }
+  }
+
+  if (proxyUrl) {
+    process.env.HTTP_PROXY = proxyUrl;
+    process.env.HTTPS_PROXY = proxyUrl;
+    process.env.ALL_PROXY = proxyUrl;
+    process.env.NINE_ROUTER_PROXY_URL = proxyUrl;
+    managed = true;
+  }
+
+  if (noProxy) {
+    process.env.NO_PROXY = noProxy;
+    process.env.NINE_ROUTER_NO_PROXY = noProxy;
+    managed = true;
+  }
+
+  if (managed) {
+    process.env.NINE_ROUTER_PROXY_MANAGED = "1";
+  } else if (wasManaged) {
+    // If we previously managed env but now cleared everything, drop the marker.
+    delete process.env.NINE_ROUTER_PROXY_MANAGED;
+  }
+}