feat: android signing guide

src/content/docs/distribute/apk-sign.mdx

@@ -0,0 +1,114 @@
+---
+title: Android APK/AAB Signing
+sidebar:
+  order: 1
+---
+
+import { Steps } from '@astrojs/starlight/components';
+
+To publish on the Play Store, you need to sign your app with a digital certificate.
+
+Android uses two signing keys: upload and app signing.
+
+Developers upload an `.aab` or `.apk` file signed with an upload key to the Play Store.
+The end-users download the `.apk` file signed with an app signing key.
+To create your app signing key, use Play App Signing as described in the [official Play Store documentation](https://support.google.com/googleplay/android-developer/answer/9842756?hl=en&visit_id=638549803861403647-3347771264&rd=1).
+
+To sign your app, use the following instructions.
+
+<Steps>
+1. Create an `upload` Keystore
+
+    If you have an existing keystore, skip to the next step. If not, create one using one of the following methods:
+
+    1.  Following the [Android Studio key generation steps](https://developer.android.com/studio/publish/app-signing#sign-apk)
+    2.  Running the following at the command line:
+        On Mac/Linux, use the following command:
+
+        ```
+        keytool -genkey -v -keystore ~/upload-keystore.jks -keyalg RSA -keysize 2048 -validity 10000 -alias upload
+        ```
+
+        On Windows, use the following command:
+
+        ```
+        keytool -genkey -v -keystore $env:USERPROFILE\upload-keystore.jks -storetype JKS -keyalg RSA -keysize 2048 -validity 10000 -alias upload
+        ```
+
+        This command stores the `upload-keystore.jks` file in your home directory. If you want to store it elsewhere, change the argument you pass to the `-keystore` parameter. However, keep the `keystore` file private; don't check it into public source control!
+
+        :::note
+
+        - The `keytool` command might not be in your path—it's part of Java, which is installed as part of Android Studio. You may find it installed in the JDK that is installed with Android Studio, for example:
+
+            - Linux: `/opt/android-studio/jbr/bin/keytool`
+            - macOS: `/Applications/Android Studio.app/Contents/jbr/Contents/Home/bin/keytool`
+            - Windows: `C:\\Program Files\\Android\\Android Studio\\jbr\\bin\\keytool.exe`
+
+            Then use that fully qualified path. If your path includes space-separated names, such as Program Files, use platform-appropriate notation for the names. For example, on Mac/Linux use `Program\ Files`, and on Windows use `"Program Files"`.
+
+        - The `-storetype JKS` tag is only required for Java 9 or newer. As of the Java 9 release, the keystore type defaults to PKS12.
+        :::
+
+3.  Reference the Keystore from the App
+
+    Create a file named `[project]/src-tauri/gen/android/keystore.properties` that contains a reference to your keystore:
+
+    ```
+    storePassword=<password from previous step>
+    keyPassword=<password from previous step>
+    keyAlias=upload
+    storeFile=<location of the key store file, such as /Users/<user name>/upload-keystore.jks or C:\\Users\\<user name>\\upload-keystore.jks>
+    ```
+
+    :::caution
+    Keep the `keystore.properties` file private; don't check it into public source control.
+    :::
+
+4.  Configure Signing in Gradle
+
+    Configure gradle to use your upload key when building your app in release mode by editing the `[project]/src-tauri/gen/android/app/build.gradle.kts` file.
+
+    1.  Add the needed imports at the beginning of the file:
+
+        ```kotlin
+        import java.util.Properties
+        import java.io.FileInputStream
+        ```
+
+    2.  Add the `release` signing config before the `buildTypes` block:
+
+        ```kotlin {3-12}
+        signingConfigs {
+            create("release") {
+                val keystorePropertiesFile = rootProject.file("keystore.properties")
+                val keystoreProperties = Properties()
+                if (keystorePropertiesFile.exists()) {
+                    keystoreProperties.load(FileInputStream(keystorePropertiesFile))
+                }
+
+                keyAlias = keystoreProperties["keyAlias"] as String
+                keyPassword = keystoreProperties["keyPassword"] as String
+                storeFile = file(keystoreProperties["storeFile"] as String)
+                storePassword = keystoreProperties["storePassword"] as String
+            }
+        }
+
+        buildTypes {
+            ...
+        }
+        ```
+
+    3.  Use the new `release` signing config in the `release` config in `buildTypes` block:
+
+        ```kotlin {3}
+        buildTypes {
+            getByName("release") {
+                signingConfig = signingConfigs.getByName("release")
+            }
+        }
+        ```
+
+</Steps>
+
+Release builds of your app will now be signed automatically.