fix: make release signing optional for CI debug builds

android/app/build.gradle.kts

@@ -7,39 +7,19 @@ plugins {
     id("com.google.gms.google-services")
 }
 
+// Release signing is intentionally optional during configuration so debug/profile
+// builds (including GitHub Actions CI) do not require private signing credentials.
 val keystoreProperties = Properties()
 val keystorePropertiesFile = rootProject.file("key.properties")
 
-if (!keystorePropertiesFile.exists()) {
-    throw GradleException(
-        "Missing android/key.properties. " +
-        "Create it from android/key.properties.template."
-    )
-}
-
-FileInputStream(keystorePropertiesFile).use {
-    keystoreProperties.load(it)
-}
-
-fun requiredKeystoreProperty(name: String): String {
-    val value = keystoreProperties.getProperty(name)?.trim()
-
-    println("MotorSignal signing property [$name]: ${if (value.isNullOrEmpty()) "<MISSING>" else "<PRESENT>"}")
-
-    if (value.isNullOrEmpty()) {
-        println("Properties actually loaded by Gradle: ${keystoreProperties.keys}")
-        throw GradleException(
-            "Missing $name in android/key.properties"
-        )
+if (keystorePropertiesFile.exists()) {
+    FileInputStream(keystorePropertiesFile).use {
+        keystoreProperties.load(it)
     }
-
-    return value
 }
 
-val releaseStorePassword = requiredKeystoreProperty("storePassword")
-val releaseKeyPassword = requiredKeystoreProperty("keyPassword")
-val releaseKeyAlias = requiredKeystoreProperty("keyAlias")
-val releaseStoreFile = requiredKeystoreProperty("storeFile")
+fun optionalKeystoreProperty(name: String): String? =
+    keystoreProperties.getProperty(name)?.trim()?.takeIf { it.isNotEmpty() }
 
 android {
     namespace = "app.motorsignal.motorcycle"
@@ -60,21 +40,38 @@ android {
     }
 
     signingConfigs {
-    create("release") {
-        keyAlias = releaseKeyAlias
-        keyPassword = releaseKeyPassword
-        storePassword = releaseStorePassword
-        storeFile = rootProject.file(releaseStoreFile)
-        storeType = "PKCS12"
+        val releaseStorePassword = optionalKeystoreProperty("storePassword")
+        val releaseKeyPassword = optionalKeystoreProperty("keyPassword")
+        val releaseKeyAlias = optionalKeystoreProperty("keyAlias")
+        val releaseStoreFile = optionalKeystoreProperty("storeFile")
+
+        if (releaseStorePassword != null &&
+            releaseKeyPassword != null &&
+            releaseKeyAlias != null &&
+            releaseStoreFile != null
+        ) {
+            create("release") {
+                keyAlias = releaseKeyAlias
+                keyPassword = releaseKeyPassword
+                storePassword = releaseStorePassword
+                storeFile = rootProject.file(releaseStoreFile)
+                storeType = "PKCS12"
+            }
+        }
     }
-}
 
     buildTypes {
-    release {
-        signingConfig = signingConfigs.getByName("release")
+        release {
+            val releaseSigningConfig = signingConfigs.findByName("release")
+                ?: throw GradleException(
+                    "Release signing is not configured. " +
+                        "Provide android/key.properties with storePassword, keyPassword, " +
+                        "keyAlias, and storeFile for a signed release build."
+                )
+            signingConfig = releaseSigningConfig
+        }
     }
 }
-}
 
 kotlin {
     compilerOptions {