Make the release build traceable: profileable, with composable names

System Tracing on the phone only records an app's own trace sections when
the app is debuggable or profileable, and the phone runs a build that is
neither once release builds exist. profileable shell="true" admits shell
profilers and nothing else. runtime-tracing names composables inside those
sections and is inert until a trace is recording.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

app/androidApp/build.gradle.kts

@@ -137,6 +137,7 @@ dependencies {
     coreLibraryDesugaring(libs.desugar.jdk.libs)
 
     implementation(libs.compose.runtime)
+    implementation(libs.compose.runtime.tracing)
     implementation(libs.compose.foundation)
     implementation(libs.compose.material3)
     implementation(libs.compose.ui)

app/androidApp/src/main/AndroidManifest.xml

@@ -29,6 +29,12 @@
         android:allowBackup="true"
         android:theme="@android:style/Theme.Material.Light.NoActionBar"
         tools:ignore="MissingApplicationIcon">
+        <!-- Lets the phone's own System Tracing see this app's trace sections
+             (Compose's phases, and the composable names runtime-tracing
+             adds) in a release build, so a frame cost measured on the real
+             device can be attributed. shell="true" limits it to profilers
+             run from the shell; it grants nothing to other apps. -->
+        <profileable android:shell="true" />
         <!-- adjustResize (not the system's default pan): the layout handles
              the keyboard itself via imePadding(), so the window must resize
              rather than slide the top bar off screen. -->

app/gradle/libs.versions.toml

@@ -68,6 +68,11 @@ androidx-exifinterface = { module = "androidx.exifinterface:exifinterface", vers
 # Declared directly rather than through the plugin's `compose.*` accessors,
 # which are deprecated as of CMP 1.11.
 compose-runtime = { module = "org.jetbrains.compose.runtime:runtime", version.ref = "compose-multiplatform" }
+# Names composables in a system trace, which is how a per-frame cost on the
+# phone gets attributed to a composable rather than to "Compose". Inert until
+# a trace is being recorded. Its own release train: 1.12.0 was the newest
+# stable on Google Maven on 2026-09-02.
+compose-runtime-tracing = { module = "androidx.compose.runtime:runtime-tracing", version = "1.12.0" }
 compose-foundation = { module = "org.jetbrains.compose.foundation:foundation", version.ref = "compose-multiplatform" }
 compose-material3 = { module = "org.jetbrains.compose.material3:material3", version.ref = "compose-material3" }
 compose-ui = { module = "org.jetbrains.compose.ui:ui", version.ref = "compose-multiplatform" }