fix: prevent null port from being misclassified as release error

When addressDetails.port is null, the ?? 0 coercion set releasePort to 0
(not undefined), causing the error handler to emit LoopbackPortReleaseError
on port 0 instead of allowing LoopbackPortAddressUnavailableError.

Only assign releasePort when the port is a valid positive number, keeping it
undefined otherwise so the error handler and close callback remain consistent.

Author: cursoragent

packages/shared/src/Net.ts

@@ -231,24 +231,19 @@ export const make = (
                   family: null,
                   port: null,
                 };
-          const port = addressDetails.port ?? 0;
+          const port =
+            addressDetails.port !== null && addressDetails.port > 0
+              ? addressDetails.port
+              : undefined;
           releasePort = port;
 
           probe.close((cause) => {
-            if (cause) {
-              settle(
-                Effect.fail(
-                  new LoopbackPortReleaseError({
-                    host,
-                    port,
-                    cause,
-                  }),
-                ),
-              );
-              return;
-            }
-            if (addressDetails.port !== null && addressDetails.port > 0) {
-              settle(Effect.succeed(addressDetails.port));
+            if (port !== undefined) {
+              if (cause) {
+                settle(Effect.fail(new LoopbackPortReleaseError({ host, port, cause })));
+                return;
+              }
+              settle(Effect.succeed(port));
               return;
             }
             settle(