chore(android): release signing via keystore.properties

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/build.gradle.kts

@@ -1,3 +1,6 @@
+import java.io.FileInputStream
+import java.util.Properties
+
 plugins {
     id("com.android.application") version "8.10.0"
     id("org.jetbrains.kotlin.android") version "1.9.20"
@@ -5,6 +8,14 @@ plugins {
     id("com.google.dagger.hilt.android") version "2.49"
 }
 
+// Release signing is driven by a git-ignored keystore.properties in the repo
+// root (see keystore.properties.example). Absent (e.g. CI / fresh clone) the
+// release build simply stays unsigned — debug builds are unaffected.
+val keystorePropsFile = rootProject.file("keystore.properties")
+val keystoreProps = Properties().apply {
+    if (keystorePropsFile.exists()) FileInputStream(keystorePropsFile).use { load(it) }
+}
+
 android {
     namespace = "com.scarriffle.calendarr"
     compileSdk = 34
@@ -20,10 +31,24 @@ android {
         vectorDrawables { useSupportLibrary = true }
     }
 
+    signingConfigs {
+        if (keystorePropsFile.exists()) {
+            create("release") {
+                storeFile = file(keystoreProps.getProperty("storeFile"))
+                storePassword = keystoreProps.getProperty("storePassword")
+                keyAlias = keystoreProps.getProperty("keyAlias")
+                keyPassword = keystoreProps.getProperty("keyPassword")
+            }
+        }
+    }
+
     buildTypes {
         release {
             isMinifyEnabled = false
             proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
+            if (keystorePropsFile.exists()) {
+                signingConfig = signingConfigs.getByName("release")
+            }
         }
     }