chore: 添加应用签名相关配置

1. 增加 .gitignore 文件中签名密钥相关的忽略规则
2. 读取 keystore.properties 配置文件
3. 配置 signingConfigs 并在 release 构建中使用签名配置

Author: mjnhmd

.gitignore

@@ -13,3 +13,8 @@
 .externalNativeBuild
 .cxx
 local.properties
+
+# Signing keys - 签名密钥相关文件(请勿提交)
+keystore.properties
+*.jks
+*.keystore

app/build.gradle.kts

@@ -1,10 +1,19 @@
+import java.util.Properties
+
 plugins {
     alias(libs.plugins.android.application)
     alias(libs.plugins.kotlin.android)
     alias(libs.plugins.kotlin.compose)
     alias(libs.plugins.ksp)
 }
 
+// 读取 keystore.properties 文件
+val keystorePropertiesFile = rootProject.file("keystore.properties")
+val keystoreProperties = Properties()
+if (keystorePropertiesFile.exists()) {
+    keystoreProperties.load(keystorePropertiesFile.inputStream())
+}
+
 android {
     namespace = "com.mjn.puzzle"
     compileSdk = 35
@@ -19,13 +28,26 @@ android {
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
 
+    // 签名配置
+    signingConfigs {
+        create("release") {
+            if (keystorePropertiesFile.exists()) {
+                keyAlias = keystoreProperties.getProperty("keyAlias")
+                keyPassword = keystoreProperties.getProperty("keyPassword")
+                storeFile = rootProject.file(keystoreProperties.getProperty("storeFile"))
+                storePassword = keystoreProperties.getProperty("storePassword")
+            }
+        }
+    }
+
     buildTypes {
         release {
             isMinifyEnabled = false
             proguardFiles(
                 getDefaultProguardFile("proguard-android-optimize.txt"),
                 "proguard-rules.pro"
             )
+            signingConfig = signingConfigs.getByName("release")
         }
     }
     compileOptions {