Fix(google-jvm): Use dynamically found port for redirect URI (#165)

The redirect URI for Google authentication on JVM was previously hardcoded to use port 8080. This change updates the implementation to use the same dynamically discovered available port that the embedded Netty server listens on.

This ensures the `redirect_uri` parameter in the authentication URL matches the actual callback server address, fixing authentication failures that would occur if port 8080 was already in use.

Author: mirzemehdi

kmpauth-google/src/jvmMain/kotlin/com/mmk/kmpauth/google/GoogleAuthUiProviderImpl.kt

@@ -25,6 +25,9 @@ import java.nio.charset.StandardCharsets
 import java.security.SecureRandom
 import java.util.Base64
 
+
+private var foundAvailablePort: Int = 8080 //TODO temporary solution. Fix later in signin by passing redirect url
+
 internal class GoogleAuthUiProviderImpl(private val credentials: GoogleAuthCredentials) :
     GoogleAuthUiProvider {
 
@@ -38,7 +41,7 @@ internal class GoogleAuthUiProviderImpl(private val credentials: GoogleAuthCrede
     ): GoogleUser? {
         val responseType = "id_token token"
         val scopeString = scopes.joinToString(" ")
-        val redirectUri = "http://localhost:8080/callback"
+        val redirectUri = "http://localhost:$foundAvailablePort/callback"
         val state: String
         var nonce: String?
         val googleAuthUrl = withContext(Dispatchers.IO) {
@@ -111,8 +114,8 @@ internal class GoogleAuthUiProviderImpl(private val credentials: GoogleAuthCrede
                 }
             }                 
         """.trimIndent()
-
-        val server = embeddedServer(Netty, port = findAvailablePort()) {
+        foundAvailablePort = findAvailablePort()
+        val server = embeddedServer(Netty, port = foundAvailablePort) {
             routing {
                 get(redirectUriPath) {
                     call.respondHtml {