feat(proxy): shorthand proxy formats + protocol header mode for bulk import

electron/package.json

@@ -28,7 +28,7 @@
     "electron-updater": "^6.8.9"
   },
   "devDependencies": {
-    "electron": "^42.5.1",
+    "electron": "^43.1.0",
     "electron-builder": "^26.15.3"
   },
   "overrides": {
@@ -42,6 +42,7 @@
     "appId": "online.omniroute.desktop",
     "productName": "OmniRoute",
     "copyright": "Copyright © 2025 OmniRoute",
+    "buildDependenciesFromSource": true,
     "directories": {
       "output": "dist-electron",
       "buildResources": "assets"

open-sse/utils/proxyDispatcher.ts

@@ -472,6 +472,12 @@ export function createProxyDispatcher(proxyUrl: string): Dispatcher {
     // valid; the cast suppresses the spurious missing-`port` error.
     dispatcher = new ProxyAgent({
       uri: cleanUri,
+      // undici 8.6+ forwards plain-HTTP requests through the proxy as an origin
+      // request (GET http://host/…) instead of a CONNECT tunnel; upstream proxies
+      // that only speak CONNECT then reject it (501). OmniRoute tunnels ALL proxied
+      // traffic (HTTP + HTTPS) via CONNECT, so force tunneling. Unknown option on
+      // undici <8.6 → silently ignored (that version already tunneled by default).
+      proxyTunnel: true,
       ...proxyDispatcherOptions,
       ...(family !== null
         ? { proxyTls: { family, autoSelectFamily: false } as ProxyAgent.Options["proxyTls"] }