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>

gradle/libs.versions.toml

@@ -0,0 +1,96 @@
+# Version catalog — single source of truth for dependency + plugin versions.
+# The full app stack (per docs/android/PLAN.md §2) is declared here so later
+# milestones (M1–M4) reference libraries by alias without re-pinning versions.
+# The M0 skeleton only wires the subset it actually compiles against.
+
+[versions]
+# Build toolchain
+agp = "8.6.1"
+kotlin = "2.0.20"
+ksp = "2.0.20-1.0.25"
+
+# AndroidX core / lifecycle / activity
+coreKtx = "1.13.1"
+lifecycle = "2.8.5"
+activityCompose = "1.9.2"
+
+# Compose
+composeBom = "2024.09.02"
+navigationCompose = "2.8.0"
+
+# DI
+hilt = "2.52"
+hiltNavigationCompose = "1.2.0"
+
+# Networking
+retrofit = "2.11.0"
+okhttp = "4.12.0"
+kotlinxSerialization = "1.7.1"
+retrofitSerializationConverter = "1.0.0"
+
+# Storage
+datastore = "1.1.1"
+securityCrypto = "1.1.0-alpha06"
+
+# Images
+coil = "2.7.0"
+
+# Testing
+junit = "4.13.2"
+androidxTestExtJunit = "1.2.1"
+espressoCore = "3.6.1"
+coroutinesTest = "1.8.1"
+
+[libraries]
+# Core / lifecycle / activity
+androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
+androidx-lifecycle-runtime-ktx = { group = "androidx.lifecycle", name = "lifecycle-runtime-ktx", version.ref = "lifecycle" }
+androidx-lifecycle-runtime-compose = { group = "androidx.lifecycle", name = "lifecycle-runtime-compose", version.ref = "lifecycle" }
+androidx-lifecycle-viewmodel-compose = { group = "androidx.lifecycle", name = "lifecycle-viewmodel-compose", version.ref = "lifecycle" }
+androidx-activity-compose = { group = "androidx.activity", name = "activity-compose", version.ref = "activityCompose" }
+
+# Compose (versions come from the BOM)
+androidx-compose-bom = { group = "androidx.compose", name = "compose-bom", version.ref = "composeBom" }
+androidx-compose-ui = { group = "androidx.compose.ui", name = "ui" }
+androidx-compose-ui-graphics = { group = "androidx.compose.ui", name = "ui-graphics" }
+androidx-compose-ui-tooling = { group = "androidx.compose.ui", name = "ui-tooling" }
+androidx-compose-ui-tooling-preview = { group = "androidx.compose.ui", name = "ui-tooling-preview" }
+androidx-compose-ui-test-manifest = { group = "androidx.compose.ui", name = "ui-test-manifest" }
+androidx-compose-ui-test-junit4 = { group = "androidx.compose.ui", name = "ui-test-junit4" }
+androidx-compose-material3 = { group = "androidx.compose.material3", name = "material3" }
+androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "navigationCompose" }
+
+# DI
+hilt-android = { group = "com.google.dagger", name = "hilt-android", version.ref = "hilt" }
+hilt-compiler = { group = "com.google.dagger", name = "hilt-compiler", version.ref = "hilt" }
+androidx-hilt-navigation-compose = { group = "androidx.hilt", name = "hilt-navigation-compose", version.ref = "hiltNavigationCompose" }
+
+# Networking
+retrofit = { group = "com.squareup.retrofit2", name = "retrofit", version.ref = "retrofit" }
+okhttp-bom = { group = "com.squareup.okhttp3", name = "okhttp-bom", version.ref = "okhttp" }
+okhttp = { group = "com.squareup.okhttp3", name = "okhttp" }
+okhttp-logging-interceptor = { group = "com.squareup.okhttp3", name = "logging-interceptor" }
+okhttp-sse = { group = "com.squareup.okhttp3", name = "okhttp-sse" }
+kotlinx-serialization-json = { group = "org.jetbrains.kotlinx", name = "kotlinx-serialization-json", version.ref = "kotlinxSerialization" }
+retrofit-kotlinx-serialization-converter = { group = "com.jakewharton.retrofit", name = "retrofit2-kotlinx-serialization-converter", version.ref = "retrofitSerializationConverter" }
+
+# Storage
+androidx-datastore-preferences = { group = "androidx.datastore", name = "datastore-preferences", version.ref = "datastore" }
+androidx-security-crypto = { group = "androidx.security", name = "security-crypto", version.ref = "securityCrypto" }
+
+# Images
+coil-compose = { group = "io.coil-kt", name = "coil-compose", version.ref = "coil" }
+
+# Testing
+junit = { group = "junit", name = "junit", version.ref = "junit" }
+kotlinx-coroutines-test = { group = "org.jetbrains.kotlinx", name = "kotlinx-coroutines-test", version.ref = "coroutinesTest" }
+androidx-test-ext-junit = { group = "androidx.test.ext", name = "junit", version.ref = "androidxTestExtJunit" }
+androidx-espresso-core = { group = "androidx.test.espresso", name = "espresso-core", version.ref = "espressoCore" }
+
+[plugins]
+android-application = { id = "com.android.application", version.ref = "agp" }
+kotlin-android = { id = "org.jetbrains.kotlin.android", version.ref = "kotlin" }
+kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "kotlin" }
+kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
+ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }
+hilt = { id = "com.google.dagger.hilt.android", version.ref = "hilt" }