feat(client/android): CI screenshot capture via Roborazzi

Play-listing/marketing screenshots of the Compose client rendered on the host JVM
by Roborazzi (Robolectric Native Graphics) — no emulator, GPU, KVM, host, or JNI
core. Five scenes render the REAL composables with embedded mock state under a
forced brand palette (Material You has no wallpaper to seed from on the JVM):
hosts grid, settings, TOFU + PIN dialogs, and the live stats HUD. Validated 5/5
locally.

- New JVM unit-test source set (app/src/test) + Roborazzi/Robolectric test deps;
  @Config(sdk=36) is mandatory (no android-all jar for compileSdk 37) and the
  animation clock is paused so a text-bearing scene reaches idle.
- kit: `-PskipRustBuild` skips the cargo-ndk native build so the JVM-only test job
  needs no Rust/NDK; normal APK/AAR builds are unchanged.
- Widen BrandDark / StatsOverlay to internal so the tests can use them.
- Standalone best-effort tag-gated workflow; PNGs upload as a 30-day artifact.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/android-screenshots.yml

@@ -0,0 +1,57 @@
+# Android client screenshots for the Play listing / marketing. Roborazzi renders the real Compose
+# UI with mock state on the host JVM via Robolectric — NO emulator, GPU, KVM, host, or JNI core
+# (`-PskipRustBuild` skips the cargo-ndk native build). The Android analogue of apple.yml's
+# `screenshots` job, gated to STABLE RELEASE tags only. Standalone + best-effort: a failure here
+# reds nothing else. PNGs land as a 30-day artifact; not committed or published.
+name: android-screenshots
+
+on:
+  push:
+    tags: ["v*"]
+  workflow_dispatch:
+
+jobs:
+  screenshots:
+    if: startsWith(github.ref, 'refs/tags/v') || github.event_name == 'workflow_dispatch'
+    runs-on: ubuntu-24.04
+    timeout-minutes: 45
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: JDK 21 (AGP 9.2 + Robolectric's SDK-36 android-all jar both want 17–21)
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: "21"
+
+      - name: Android SDK
+        uses: android-actions/setup-android@v3
+
+      # No NDK/CMake — the screenshot unit tests are pure JVM. compileSdk 37 auto-downloads via AGP
+      # if the platform channel lacks it (same note as android.yml).
+      - name: platform-tools + platform 36 + build-tools
+        run: sdkmanager "platform-tools" "platforms;android-36" "build-tools;37.0.0"
+
+      - name: Cache (gradle)
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: android-screenshots-${{ hashFiles('clients/android/**/*.gradle.kts') }}
+          restore-keys: android-screenshots-
+
+      # Roborazzi renders Compose on the JVM (Robolectric Native Graphics). `-PskipRustBuild` keeps
+      # the cargo-ndk native build out of the graph — the tests never load libpunktfunk_android.so.
+      - name: Capture screenshots (Roborazzi)
+        working-directory: clients/android
+        run: ./gradlew :app:testDebugUnitTest -PskipRustBuild --stacktrace
+
+      - name: Upload screenshots
+        if: always()
+        # v3: Gitea's API rejects upload-artifact@v4 (see apple.yml). Download is a zip.
+        uses: actions/upload-artifact@v3
+        with:
+          name: punktfunk-android-screenshots
+          path: clients/android/app/build/outputs/roborazzi
+          retention-days: 30

clients/android/app/build.gradle.kts

@@ -62,6 +62,10 @@ android {
 
     buildFeatures { compose = true }
 
+    // Roborazzi/Robolectric render Compose on the host JVM (the CI screenshot harness) and need the
+    // merged Android resources + the app's manifest/theme available to the unit tests.
+    testOptions { unitTests { isIncludeAndroidResources = true } }
+
     compileOptions {
         sourceCompatibility = JavaVersion.VERSION_21
         targetCompatibility = JavaVersion.VERSION_21
@@ -99,4 +103,21 @@ dependencies {
     // Android TV components (we target phone + TV) land in the TV-UI milestone:
     //   implementation("androidx.tv:tv-material:1.1.0")
     // The manifest already declares leanback so the scaffold installs on TV.
+
+    // --- CI screenshot harness (Roborazzi on the JVM via Robolectric — no emulator/GPU). The
+    // screenshot tests render the real Compose UI with mock state; never load the JNI core, so the
+    // job runs `:app:testDebugUnitTest -PskipRustBuild` (see kit/build.gradle.kts). ---
+    testImplementation(composeBom)
+    testImplementation("androidx.compose.ui:ui-test-junit4")
+    debugImplementation("androidx.compose.ui:ui-test-manifest") // the ComponentActivity test host
+    testImplementation("junit:junit:4.13.2")
+    testImplementation("org.robolectric:robolectric:4.16.1")
+    testImplementation("io.github.takahirom.roborazzi:roborazzi:1.64.0")
+    testImplementation("io.github.takahirom.roborazzi:roborazzi-compose:1.64.0")
+}
+
+// Record (write) the screenshots when the unit tests run. These tests exist to GENERATE marketing
+// images, not to diff goldens, so always capture rather than verify.
+tasks.withType<Test>().configureEach {
+    systemProperty("roborazzi.test.record", "true")
 }

clients/android/app/src/main/kotlin/io/unom/punktfunk/StreamScreen.kt

@@ -319,7 +319,7 @@ fun StreamScreen(handle: Long, micEnabled: Boolean, onDisconnect: () -> Unit) {
  * `[fps, mbps, latP50Ms, latP95Ms, latValid, skew, w, h, hz, dropped]`.
  */
 @Composable
-private fun StatsOverlay(s: DoubleArray, modifier: Modifier = Modifier) {
+internal fun StatsOverlay(s: DoubleArray, modifier: Modifier = Modifier) {
     if (s.size < 10) return
     val w = s[6].toInt()
     val h = s[7].toInt()

clients/android/app/src/main/kotlin/io/unom/punktfunk/Theme.kt

@@ -10,7 +10,9 @@ import androidx.compose.ui.platform.LocalContext
 
 // punktfunk brand violets (from the app icon: #6C5BF3 / #A79FF8 / #D2C9FB on a #16132A indigo).
 // Used as the fallback dark scheme on pre-Android-12 devices; on 12+ we defer to Material You.
-private val BrandDark = darkColorScheme(
+// `internal` (not private) so the CI screenshot tests can force the deterministic brand palette —
+// Material You dynamic colour has no wallpaper to seed from under the Robolectric JVM renderer.
+internal val BrandDark = darkColorScheme(
     primary = Color(0xFFA79FF8),
     onPrimary = Color(0xFF1B1442),
     primaryContainer = Color(0xFF4C3FB3),

clients/android/app/src/test/kotlin/io/unom/punktfunk/screenshots/ScreenshotTest.kt

@@ -0,0 +1,74 @@
+package io.unom.punktfunk.screenshots
+
+import androidx.activity.ComponentActivity
+import androidx.compose.ui.test.junit4.createAndroidComposeRule
+import androidx.compose.ui.test.onRoot
+import com.github.takahirom.roborazzi.captureRoboImage
+import com.github.takahirom.roborazzi.captureScreenRoboImage
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import org.robolectric.annotation.GraphicsMode
+
+/**
+ * App-store / marketing screenshots of the native Android client, rendered on the JVM by Roborazzi
+ * (Robolectric Native Graphics) — no emulator, GPU, host, or JNI core. The scenes (ShotScenes.kt)
+ * render the REAL Compose UI with mock state.
+ *
+ * `sdk = [36]` is mandatory: Robolectric ships android-all jars only up to API 36 (Android 16), and
+ * the app's compileSdk is 37. PNGs land in build/outputs/roborazzi/.
+ */
+@RunWith(RobolectricTestRunner::class)
+@GraphicsMode(GraphicsMode.Mode.NATIVE)
+@Config(sdk = [36], qualifiers = "w360dp-h800dp-xxhdpi")
+class ScreenshotTest {
+    @get:Rule
+    val compose = createAndroidComposeRule<ComponentActivity>()
+
+    private val out = "build/outputs/roborazzi"
+
+    // Pausing the animation clock before composing (then advancing once past the entrance animation
+    // and freezing) is what makes a text-field-bearing scene capturable: a focused field blinks its
+    // cursor via an infinite animation that otherwise keeps Compose perpetually "busy", so
+    // setContent's wait-for-idle never returns. Frozen, the capture is also deterministic.
+
+    /** Full-screen content scenes: the compose root fills the device, so a root capture is the shot. */
+    private fun shootRoot(name: String, content: @androidx.compose.runtime.Composable () -> Unit) {
+        compose.mainClock.autoAdvance = false
+        compose.setContent { ShotTheme(content) }
+        compose.mainClock.advanceTimeBy(800)
+        compose.onRoot().captureRoboImage("$out/phone-$name.png")
+    }
+
+    /** Dialog scenes: the AlertDialog is a separate window, so capture the whole screen (all windows). */
+    private fun shootScreen(name: String, content: @androidx.compose.runtime.Composable () -> Unit) {
+        compose.mainClock.autoAdvance = false
+        compose.setContent { ShotTheme(content) }
+        compose.mainClock.advanceTimeBy(800)
+        captureScreenRoboImage("$out/phone-$name.png")
+    }
+
+    @Test
+    fun hosts() = shootRoot("hosts") { HostsScene() }
+
+    @Test
+    fun settings() = shootRoot("settings") { SettingsScene() }
+
+    @Test
+    @Config(sdk = [36], qualifiers = "w800dp-h360dp-xxhdpi") // landscape — the stream is immersive
+    fun stream() = shootRoot("stream") { StreamScene() }
+
+    @Test
+    fun trust() = shootScreen("trust") {
+        HostsScene()
+        TrustDialog()
+    }
+
+    @Test
+    fun pair() = shootScreen("pair") {
+        HostsScene()
+        PairDialog()
+    }
+}

clients/android/app/src/test/kotlin/io/unom/punktfunk/screenshots/ShotScenes.kt

@@ -0,0 +1,195 @@
+package io.unom.punktfunk.screenshots
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.grid.GridCells
+import androidx.compose.foundation.lazy.grid.GridItemSpan
+import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
+import androidx.compose.foundation.lazy.grid.items
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Surface
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Brush
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import io.unom.punktfunk.BrandDark
+import io.unom.punktfunk.Settings
+import io.unom.punktfunk.SettingsScreen
+import io.unom.punktfunk.StatsOverlay
+import io.unom.punktfunk.components.HostCard
+import io.unom.punktfunk.components.SectionLabel
+import io.unom.punktfunk.models.HostStatus
+
+// The CI screenshot scenes: the REAL app composables, fed embedded mock state, under the forced
+// brand palette (Material You has no wallpaper to seed from on the JVM). The stream-video surface
+// and ConnectScreen/App are intentionally absent — they require the live JNI core / a session.
+
+/** Forces the deterministic punktfunk brand scheme (see Theme.kt) instead of dynamic colour. */
+@Composable
+internal fun ShotTheme(content: @Composable () -> Unit) {
+    MaterialTheme(colorScheme = BrandDark, content = content)
+}
+
+private data class MockHost(val name: String, val address: String, val status: HostStatus)
+
+private val SAVED = listOf(
+    MockHost("Living Room PC", "192.168.1.42:9777", HostStatus.PAIRED),
+    MockHost("Office", "192.168.1.50:9777", HostStatus.TOFU),
+)
+private val DISCOVERED = listOf(
+    MockHost("studio-deck", "192.168.1.61:9777", HostStatus.PAIRING),
+    MockHost("HTPC", "192.168.1.70:9777", HostStatus.TOFU),
+)
+
+/** The connect screen's host grid, reconstructed from the real HostCard/SectionLabel components. */
+@Composable
+internal fun HostsScene() {
+    Surface(Modifier.fillMaxSize(), color = MaterialTheme.colorScheme.background) {
+        LazyVerticalGrid(
+            columns = GridCells.Adaptive(minSize = 160.dp),
+            modifier = Modifier.fillMaxSize(),
+            contentPadding = androidx.compose.foundation.layout.PaddingValues(16.dp),
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+            verticalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            item(span = { GridItemSpan(maxLineSpan) }) {
+                Column(
+                    horizontalAlignment = Alignment.CenterHorizontally,
+                    modifier = Modifier.fillMaxWidth(),
+                ) {
+                    Spacer(Modifier.height(8.dp))
+                    Text("Punktfunk", style = MaterialTheme.typography.headlineLarge)
+                    Text(
+                        "stream a remote desktop",
+                        style = MaterialTheme.typography.bodyMedium,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                    Spacer(Modifier.height(24.dp))
+                }
+            }
+            item(span = { GridItemSpan(maxLineSpan) }) { SectionLabel("Saved hosts") }
+            items(SAVED) { h ->
+                HostCard(h.name, h.address, h.status, enabled = true, onConnect = {}, onForget = {}, onRename = {})
+            }
+            item(span = { GridItemSpan(maxLineSpan) }) {
+                Spacer(Modifier.height(12.dp))
+                SectionLabel("Discovered on the network")
+            }
+            items(DISCOVERED) { h ->
+                HostCard(h.name, h.address, h.status, enabled = true, onConnect = {}, onForget = null)
+            }
+        }
+    }
+}
+
+/** The real SettingsScreen, fed a representative non-default Settings. */
+@Composable
+internal fun SettingsScene() {
+    Surface(Modifier.fillMaxSize(), color = MaterialTheme.colorScheme.background) {
+        SettingsScreen(
+            initial = Settings(
+                width = 1920,
+                height = 1080,
+                hz = 120,
+                bitrateKbps = 50_000,
+                compositor = 1,
+                gamepad = 2,
+                micEnabled = true,
+                statsHudEnabled = true,
+                trackpadMode = true,
+            ),
+            onChange = {},
+            onBack = {},
+        )
+    }
+}
+
+/** The real TOFU AlertDialog (mirrors ConnectScreen's PendingTrust.Kind.TRUST_NEW), shown over the host grid. */
+@Composable
+internal fun TrustDialog() {
+    AlertDialog(
+        onDismissRequest = {},
+        title = { Text("Trust this host?") },
+        text = {
+            Column {
+                Text("First connection to 192.168.1.61:9777.")
+                Text("Fingerprint 9f8e7d6c5b4a3928…")
+                Text(
+                    "This host allows trust-on-first-use, but that can't tell an impostor " +
+                        "from the real host. Pairing with a PIN is stronger — it proves both sides.",
+                )
+            }
+        },
+        confirmButton = { TextButton({}) { Text("Trust (TOFU)") } },
+        dismissButton = { TextButton({}) { Text("Pair with PIN…") } },
+    )
+}
+
+/** The PIN-pairing AlertDialog (mirrors ConnectScreen's PendingTrust.Kind.PAIR). The live screen
+ *  uses OutlinedTextFields, but a TextField inside a Dialog window never reaches idle under
+ *  Robolectric (its focus/cursor machinery animates forever) — so the PIN is shown as a static
+ *  display here, which also reads better in a marketing shot. */
+@Composable
+internal fun PairDialog() {
+    AlertDialog(
+        onDismissRequest = {},
+        title = { Text("Pair with PIN") },
+        text = {
+            Column {
+                Text("Enter the 4-digit PIN shown on the host.")
+                Spacer(Modifier.height(16.dp))
+                Surface(
+                    color = MaterialTheme.colorScheme.surfaceVariant,
+                    shape = MaterialTheme.shapes.medium,
+                    modifier = Modifier.fillMaxWidth(),
+                ) {
+                    Text(
+                        "4  8  2  7",
+                        style = MaterialTheme.typography.headlineMedium,
+                        textAlign = TextAlign.Center,
+                        modifier = Modifier.fillMaxWidth().padding(vertical = 16.dp),
+                    )
+                }
+                Spacer(Modifier.height(12.dp))
+                Text(
+                    "This device: Pixel 9 Pro",
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+            }
+        },
+        confirmButton = { TextButton({}) { Text("Pair") } },
+        dismissButton = { TextButton({}) { Text("Cancel") } },
+    )
+}
+
+/** The live stats HUD (the real StatsOverlay) over a synthetic "streamed frame" gradient. */
+@Composable
+internal fun StreamScene() {
+    Box(
+        Modifier
+            .fillMaxSize()
+            .background(
+                Brush.linearGradient(listOf(Color(0xFF2A1E5C), Color(0xFF0E1B3D), Color(0xFF06122B))),
+            ),
+    ) {
+        // [fps, mbps, latP50, latP95, latValid, skew, w, h, hz, dropped]
+        StatsOverlay(
+            doubleArrayOf(238.0, 921.4, 1.3, 2.1, 1.0, 1.0, 5120.0, 1440.0, 240.0, 0.0),
+            Modifier.align(Alignment.TopStart).padding(12.dp),
+        )
+    }
+}

clients/android/kit/build.gradle.kts

@@ -99,6 +99,12 @@ val cargoNdkDebug = registerCargoNdk("cargoNdkDebug", release = false)
 val cargoNdkRelease = registerCargoNdk("cargoNdkRelease", release = true)
 
 afterEvaluate {
-    tasks.named("preDebugBuild").configure { dependsOn(cargoNdkDebug) }
+    // `-PskipRustBuild` skips the cargo-ndk native build — for JVM-only tasks (the Roborazzi
-    tasks.named("preReleaseBuild").configure { dependsOn(cargoNdkRelease) }
+    // screenshot unit tests render Compose on the JVM and never load libpunktfunk_android.so), so
+    // CI/local screenshot runs don't need the Rust toolchain or NDK. The native build stays wired
+    // for every normal APK/AAR build.
+    if (!project.hasProperty("skipRustBuild")) {
+        tasks.named("preDebugBuild").configure { dependsOn(cargoNdkDebug) }
+        tasks.named("preReleaseBuild").configure { dependsOn(cargoNdkRelease) }
+    }
 }