refactor: move package "internal" to "debug" and improve logging throughout the codebase

gropify-gradle-plugin/src/main/kotlin/com/highcapable/gropify/debug/Exception.kt

@@ -0,0 +1,53 @@
+/*
+ * Gropify - A type-safe and modern properties plugin for Gradle.
+ * Copyright (C) 2019 HighCapable
+ * https://github.com/HighCapable/Gropify
+ *
+ * Apache License Version 2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * This file is created by fankes on 2025/10/16.
+ */
+@file:Suppress("UnusedReceiverParameter")
+
+package com.highcapable.gropify.debug
+
+import com.highcapable.gropify.plugin.Gropify
+import kotlin.contracts.ExperimentalContracts
+import kotlin.contracts.contract
+
+/**
+ * Gropify exception.
+ */
+internal class GropifyException(message: String) : IllegalStateException("Gropify was ran into an error: $message")
+
+/**
+ * Throws a [GropifyException] with the specified [message].
+ */
+internal fun Gropify.error(message: String): Nothing = throw GropifyException(message)
+
+/**
+ * Requires that a condition is true. If it is not, throws a [GropifyException] with the result of
+ * calling the specified [lazyMessage] function.
+ */
+@OptIn(ExperimentalContracts::class)
+internal fun Gropify.require(value: Boolean, lazyMessage: () -> Any) {
+    contract {
+        returns() implies value
+    }
+    if (!value) {
+        val message = lazyMessage()
+        throw GropifyException(message.toString())
+    }
+}