chore(scaffold): M0 Gradle + Compose + Hilt skeleton with CI

Stand up the Android-app repo per docs/android/PLAN.md M0: a buildable
Kotlin + Jetpack Compose (Material 3) single-activity skeleton wired for
Hilt, ready for the M1-M4 functional pass.

- Gradle 8.7 wrapper; AGP 8.6.1 / Kotlin 2.0.20, JDK 17, minSdk 29, target 35.
- Version catalog (gradle/libs.versions.toml) pins the full planned stack
  (Compose, Hilt, Retrofit/OkHttp + kotlinx.serialization, DataStore,
  security-crypto, Coil, Navigation) so later milestones reference by alias.
- RunicGatewayApp (@HiltAndroidApp) + MainActivity (Compose) + ui/theme/*.
- Strings externalized from day one; adaptive launcher icon; backup rules
  exclude the token store / DataStore (no session material off-device).
- CI: .gitea/workflows/pr-checks.yml gates PRs with lint + test + assembleDebug
  (JDK 17 + Android SDK on the self-hosted runner; debug builds auto-signed,
  no secrets). Placeholder JVM unit test so the test gate runs.
- .gitattributes forces LF on gradlew so the wrapper runs on the Linux runner.

Verified locally: `gradle help`/`projects` configure the :app module and
resolve all six plugins cleanly (full assemble needs the Android SDK, done in CI).

app id: com.runicgateway.app (PLAN.md §13, pending runicgateway.app domain).

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

app/build.gradle.kts

@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+plugins {
+    alias(libs.plugins.android.application)
+    alias(libs.plugins.kotlin.android)
+    alias(libs.plugins.kotlin.compose)
+    alias(libs.plugins.kotlin.serialization)
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.hilt)
+}
+
+android {
+    namespace = "com.runicgateway.app"
+    compileSdk = 35
+
+    defaultConfig {
+        // Target application id per docs/android/PLAN.md §13 (pending runicgateway.app domain).
+        applicationId = "com.runicgateway.app"
+        minSdk = 29
+        targetSdk = 35
+        versionCode = 1
+        versionName = "0.1.0"
+
+        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
+    }
+
+    buildTypes {
+        release {
+            // Signing/minification are wired at M6 (release hardening). Debug is auto-signed.
+            isMinifyEnabled = false
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro",
+            )
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = "17"
+    }
+
+    buildFeatures {
+        compose = true
+        buildConfig = true
+    }
+
+    packaging {
+        resources {
+            excludes += "/META-INF/{AL2.0,LGPL2.1}"
+        }
+    }
+}
+
+dependencies {
+    // Core / lifecycle / activity
+    implementation(libs.androidx.core.ktx)
+    implementation(libs.androidx.lifecycle.runtime.ktx)
+    implementation(libs.androidx.lifecycle.runtime.compose)
+    implementation(libs.androidx.lifecycle.viewmodel.compose)
+    implementation(libs.androidx.activity.compose)
+
+    // Compose (BOM-managed versions)
+    implementation(platform(libs.androidx.compose.bom))
+    implementation(libs.androidx.compose.ui)
+    implementation(libs.androidx.compose.ui.graphics)
+    implementation(libs.androidx.compose.ui.tooling.preview)
+    implementation(libs.androidx.compose.material3)
+    implementation(libs.androidx.navigation.compose)
+    debugImplementation(libs.androidx.compose.ui.tooling)
+    debugImplementation(libs.androidx.compose.ui.test.manifest)
+
+    // DI
+    implementation(libs.hilt.android)
+    ksp(libs.hilt.compiler)
+    implementation(libs.androidx.hilt.navigation.compose)
+
+    // Networking (wired for M1+; declared now so the stack resolves)
+    implementation(libs.retrofit)
+    implementation(platform(libs.okhttp.bom))
+    implementation(libs.okhttp)
+    implementation(libs.okhttp.logging.interceptor)
+    implementation(libs.okhttp.sse)
+    implementation(libs.kotlinx.serialization.json)
+    implementation(libs.retrofit.kotlinx.serialization.converter)
+
+    // Storage
+    implementation(libs.androidx.datastore.preferences)
+    implementation(libs.androidx.security.crypto)
+
+    // Images
+    implementation(libs.coil.compose)
+
+    // Unit tests
+    testImplementation(libs.junit)
+    testImplementation(libs.kotlinx.coroutines.test)
+
+    // Instrumented tests
+    androidTestImplementation(libs.androidx.test.ext.junit)
+    androidTestImplementation(libs.androidx.espresso.core)
+    androidTestImplementation(platform(libs.androidx.compose.bom))
+    androidTestImplementation(libs.androidx.compose.ui.test.junit4)
+}

app/proguard-rules.pro

@@ -0,0 +1,3 @@
+# Runic Gateway Android app — ProGuard/R8 rules.
+# Minification is disabled until M6 (release hardening); real keep rules for
+# kotlinx.serialization DTOs and Retrofit models are added there.

app/src/main/AndroidManifest.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <!-- The app is purely an HTTPS API client of a shard's website backend. -->
+    <uses-permission android:name="android.permission.INTERNET" />
+    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
+
+    <application
+        android:name=".RunicGatewayApp"
+        android:allowBackup="true"
+        android:dataExtractionRules="@xml/data_extraction_rules"
+        android:fullBackupContent="@xml/backup_rules"
+        android:icon="@mipmap/ic_launcher"
+        android:label="@string/app_name"
+        android:roundIcon="@mipmap/ic_launcher_round"
+        android:supportsRtl="true"
+        android:theme="@style/Theme.RunicGateway">
+
+        <activity
+            android:name=".MainActivity"
+            android:exported="true"
+            android:label="@string/app_name"
+            android:theme="@style/Theme.RunicGateway">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+    </application>
+
+</manifest>

app/src/main/java/com/runicgateway/app/MainActivity.kt

@@ -0,0 +1,64 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app
+
+import android.os.Bundle
+import androidx.activity.ComponentActivity
+import androidx.activity.compose.setContent
+import androidx.activity.enableEdgeToEdge
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import com.runicgateway.app.ui.theme.RunicGatewayTheme
+import dagger.hilt.android.AndroidEntryPoint
+
+/**
+ * Single-activity host. Navigation-Compose and the first-run base-URL flow (§3)
+ * land in M1; this M0 skeleton only proves the Compose + Hilt + theme wiring.
+ */
+@AndroidEntryPoint
+class MainActivity : ComponentActivity() {
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        enableEdgeToEdge()
+        setContent {
+            RunicGatewayTheme {
+                Scaffold(modifier = Modifier.fillMaxSize()) { innerPadding ->
+                    Placeholder(modifier = Modifier.padding(innerPadding))
+                }
+            }
+        }
+    }
+}
+
+@Composable
+private fun Placeholder(modifier: Modifier = Modifier) {
+    Column(
+        modifier = modifier.fillMaxSize(),
+        horizontalAlignment = Alignment.CenterHorizontally,
+        verticalArrangement = Arrangement.Center,
+    ) {
+        Text(
+            text = stringResource(id = R.string.app_scaffold_ready),
+            style = MaterialTheme.typography.titleLarge,
+        )
+    }
+}
+
+@Preview(showBackground = true)
+@Composable
+private fun PlaceholderPreview() {
+    RunicGatewayTheme {
+        Placeholder()
+    }
+}

app/src/main/java/com/runicgateway/app/RunicGatewayApp.kt

@@ -0,0 +1,15 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ * Runic Gateway — native Android client of a shard's website API.
+ */
+package com.runicgateway.app
+
+import android.app.Application
+import dagger.hilt.android.HiltAndroidApp
+
+/**
+ * Application entry point. Annotated for Hilt so the DI graph is available
+ * to activities, view models, and (from M1) repositories / API services.
+ */
+@HiltAndroidApp
+class RunicGatewayApp : Application()

app/src/main/java/com/runicgateway/app/ui/theme/Color.kt

@@ -0,0 +1,16 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.theme
+
+import androidx.compose.ui.graphics.Color
+
+// Placeholder palette for the M0 skeleton. The M5 design pass replaces this and
+// derives Material 3 colors from each shard's per-install branding (PLAN.md §3, §5).
+val Purple80 = Color(0xFFD0BCFF)
+val PurpleGrey80 = Color(0xFFCCC2DC)
+val Pink80 = Color(0xFFEFB8C8)
+
+val Purple40 = Color(0xFF6650A4)
+val PurpleGrey40 = Color(0xFF625B71)
+val Pink40 = Color(0xFF7D5260)

app/src/main/java/com/runicgateway/app/ui/theme/Theme.kt

@@ -0,0 +1,53 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.theme
+
+import android.os.Build
+import androidx.compose.foundation.isSystemInDarkTheme
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.darkColorScheme
+import androidx.compose.material3.dynamicDarkColorScheme
+import androidx.compose.material3.dynamicLightColorScheme
+import androidx.compose.material3.lightColorScheme
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.platform.LocalContext
+
+private val DarkColorScheme = darkColorScheme(
+    primary = Purple80,
+    secondary = PurpleGrey80,
+    tertiary = Pink80,
+)
+
+private val LightColorScheme = lightColorScheme(
+    primary = Purple40,
+    secondary = PurpleGrey40,
+    tertiary = Pink40,
+)
+
+/**
+ * App theme for the M0 skeleton. Dynamic color (Android 12+) is used when
+ * available; otherwise a static placeholder scheme. The M5 design pass wires
+ * the color scheme to per-shard branding (PLAN.md §3, §5).
+ */
+@Composable
+fun RunicGatewayTheme(
+    darkTheme: Boolean = isSystemInDarkTheme(),
+    dynamicColor: Boolean = true,
+    content: @Composable () -> Unit,
+) {
+    val colorScheme = when {
+        dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
+            val context = LocalContext.current
+            if (darkTheme) dynamicDarkColorScheme(context) else dynamicLightColorScheme(context)
+        }
+        darkTheme -> DarkColorScheme
+        else -> LightColorScheme
+    }
+
+    MaterialTheme(
+        colorScheme = colorScheme,
+        typography = Typography,
+        content = content,
+    )
+}

app/src/main/java/com/runicgateway/app/ui/theme/Type.kt

@@ -0,0 +1,21 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app.ui.theme
+
+import androidx.compose.material3.Typography
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.sp
+
+// Default Material 3 type scale for the skeleton; refined in the M5 design pass.
+val Typography = Typography(
+    bodyLarge = TextStyle(
+        fontFamily = FontFamily.Default,
+        fontWeight = FontWeight.Normal,
+        fontSize = 16.sp,
+        lineHeight = 24.sp,
+        letterSpacing = 0.5.sp,
+    ),
+)

app/src/main/res/drawable/ic_launcher_foreground.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<!-- Placeholder launcher glyph: a stylized gateway arch. Replaced in the M5 design pass. -->
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="108dp"
+    android:height="108dp"
+    android:viewportWidth="108"
+    android:viewportHeight="108">
+    <path
+        android:fillColor="#D0BCFF"
+        android:pathData="M38,74 L38,50 A16,16 0 0,1 70,50 L70,74 L62,74 L62,50 A8,8 0 0,0 46,50 L46,74 Z" />
+    <path
+        android:fillColor="#EFB8C8"
+        android:pathData="M52,34 L56,34 L56,40 L52,40 Z M50,40 L58,40 L58,44 L50,44 Z" />
+</vector>

app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+    <monochrome android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>

app/src/main/res/mipmap-anydpi-v26/ic_launcher_round.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+    <background android:drawable="@color/ic_launcher_background" />
+    <foreground android:drawable="@drawable/ic_launcher_foreground" />
+    <monochrome android:drawable="@drawable/ic_launcher_foreground" />
+</adaptive-icon>

app/src/main/res/values/colors.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<resources>
+    <color name="ic_launcher_background">#1B1033</color>
+</resources>

app/src/main/res/values/strings.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<!--
+  All user-facing strings are externalized from day one (PLAN.md §2): English is
+  the only bundled locale, but the structure invites community translations.
+  No hardcoded UI strings in Kotlin.
+-->
+<resources>
+    <!-- Fixed launcher name, baked at build even though in-app branding is per-shard (PLAN.md §13). -->
+    <string name="app_name">Runic Gateway</string>
+    <string name="app_scaffold_ready">Runic Gateway — scaffold ready</string>
+</resources>

app/src/main/res/values/themes.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<!--
+  Base XML theme used by the manifest before Compose takes over. The live UI
+  theme is defined in Kotlin (ui/theme/Theme.kt); this only sets the window
+  background / status-bar behavior for launch.
+-->
+<resources>
+    <style name="Theme.RunicGateway" parent="android:Theme.Material.Light.NoActionBar" />
+</resources>

app/src/main/res/xml/backup_rules.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<!--
+  Auto Backup rules (API 29 uses this). Exclude the encrypted token store and
+  DataStore prefs so session material is never carried off-device in a backup.
+-->
+<full-backup-content>
+    <exclude domain="sharedpref" path="." />
+    <exclude domain="file" path="datastore/" />
+</full-backup-content>

app/src/main/res/xml/data_extraction_rules.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- SPDX-License-Identifier: GPL-3.0-or-later -->
+<!--
+  Android 12+ backup / device-transfer rules. Same posture as backup_rules.xml:
+  never transfer session tokens or DataStore prefs off-device.
+-->
+<data-extraction-rules>
+    <cloud-backup>
+        <exclude domain="sharedpref" path="." />
+        <exclude domain="file" path="datastore/" />
+    </cloud-backup>
+    <device-transfer>
+        <exclude domain="sharedpref" path="." />
+        <exclude domain="file" path="datastore/" />
+    </device-transfer>
+</data-extraction-rules>

app/src/test/java/com/runicgateway/app/ScaffoldSanityTest.kt

@@ -0,0 +1,25 @@
+/*
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+package com.runicgateway.app
+
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Placeholder JVM unit test so the `test` CI gate has something to run in M0.
+ * Real repository / view-model tests arrive with the functional pass (M1+).
+ */
+class ScaffoldSanityTest {
+    @Test
+    fun applicationIdMatchesNamespace() {
+        assertEquals("com.runicgateway.app", BuildConfig.APPLICATION_ID)
+    }
+
+    @Test
+    fun buildConfigIsDebuggableInTest() {
+        // Unit tests run against the debug variant.
+        assertTrue(BuildConfig.DEBUG)
+    }
+}