pin the android sdk explicitly and apply review fixes

- flake: pin build-tools and platform-tools to 37.0.0 instead of "latest", matching build.gradle.kts
- robolectric: run at sdk 35 (targetSdk) and re-record the golden
- manifest: allowBackup off, drop not-yet-used permissions
- theme: drop no-op status/nav bar colors (edge-to-edge)
- deps: kotlin 2.1.20, drop unused deps and test runner
- wrapper: regenerate jar from 8.11.1, add distributionSha256Sum
- remove stale README

app/build.gradle.kts

@@ -16,7 +16,6 @@ android {
         targetSdk = 35
         versionCode = 1
         versionName = "0.1.0"
-        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }
 
     buildFeatures {
@@ -59,11 +58,6 @@ dependencies {
     implementation(libs.androidx.compose.ui.graphics)
     implementation(libs.androidx.compose.ui.tooling.preview)
     implementation(libs.androidx.compose.material3)
-    implementation(libs.androidx.navigation.compose)
-    implementation(libs.koin.android)
-    implementation(libs.koin.androidx.compose)
-    implementation(libs.kotlinx.coroutines.android)
-    implementation(libs.kotlinx.serialization.json)
 
     debugImplementation(libs.androidx.compose.ui.tooling)
     debugImplementation(libs.androidx.compose.ui.test.manifest)