Proxy server to inject shim (#178)

things to test:

- [x] allow real URL to open in new window
- [x] packaging in electron?
- [ ] does it work on windows?
- [x] make sure it works with older apps
- [x] what about cache / reuse? - maybe use a bigger range of ports??

src/ipc/utils/port_utils.ts

@@ -0,0 +1,48 @@
+import net from "net";
+
+export function findAvailablePort(
+  minPort: number,
+  maxPort: number,
+): Promise<number> {
+  return new Promise((resolve, reject) => {
+    let attempts = 0;
+    const maxAttempts = 3;
+
+    function tryPort() {
+      if (attempts >= maxAttempts) {
+        reject(
+          new Error(
+            `Failed to find an available port after ${maxAttempts} attempts.`,
+          ),
+        );
+        return;
+      }
+
+      attempts++;
+      const port =
+        Math.floor(Math.random() * (maxPort - minPort + 1)) + minPort;
+      const server = net.createServer();
+
+      server.once("error", (err: any) => {
+        if (err.code === "EADDRINUSE") {
+          // Port is in use, try another one
+          console.log(`Port ${port} is in use, trying another...`);
+          server.close(() => tryPort());
+        } else {
+          // Other error
+          server.close(() => reject(err));
+        }
+      });
+
+      server.once("listening", () => {
+        server.close(() => {
+          resolve(port);
+        });
+      });
+
+      server.listen(port, "localhost");
+    }
+
+    tryPort();
+  });
+}