fix: align error handler port validation with close callback

The error handler in reserveLoopbackPort only checked
addressDetails.port !== null && addressDetails.port > 0, while the
close callback used stricter validation (Number.isInteger, > 0,
<= 65535). This inconsistency meant an invalid port (non-integer or
out-of-range) could produce LoopbackPortReleaseError via the error
path but LoopbackPortAddressUnavailableError via the close path.

Apply the same strict validation in both places.

Author: cursoragent

packages/shared/src/Net.ts

@@ -218,7 +218,10 @@ export const make = (
           Effect.fail(
             addressDetails === undefined
               ? new LoopbackPortListenError({ host, cause })
-              : addressDetails.port !== null && addressDetails.port > 0
+              : addressDetails.port !== null &&
+                  Number.isInteger(addressDetails.port) &&
+                  addressDetails.port > 0 &&
+                  addressDetails.port <= 65_535
                 ? new LoopbackPortReleaseError({ host, port: addressDetails.port, cause })
                 : new LoopbackPortAddressUnavailableError({
                     host,