chore(deps): update all libraries and Gradle to latest stable versions

Bump the version catalog, Gradle wrapper, and convention plugins to the
latest stable releases. Verified with `./gradlew assembleDebug test`
(BUILD SUCCESSFUL, 21 unit tests pass).

Toolchain:
- Gradle 9.1.0 -> 9.5.1
- AGP 9.0.1 -> 9.2.1
- Kotlin 2.3.20 -> 2.4.0

Libraries:
- androidx-core 1.18.0 -> 1.19.0, appcompat 1.7.0 -> 1.7.1,
  fragment 1.8.5 -> 1.8.9, navigation 2.9.0 -> 2.9.8
- compose-bom 2026.03.01 -> 2026.05.01, material 1.12.0 -> 1.14.0
- coroutines 1.10.2 -> 1.11.0, serialization 1.8.1 -> 1.11.0,
  collections-immutable 0.3.8 -> 0.5.0
- koin 4.1.0 -> 4.2.1, ktor 3.1.3 -> 3.5.0, coil 3.1.0 -> 3.5.0
- JUnit 5.11.4 -> 6.1.0, turbine 1.2.0 -> 1.2.1, mockk 1.14.3 -> 1.14.11

Required side-effect:
- compileSdk 36 -> 37 (mandated by androidx.core 1.19.0); targetSdk
  left at 36.

Also refresh stale JUnit 5 / AGP 9.0 / compileSdk 36 references in the
README and convention-plugin docs.

gradle/libs.versions.toml

@@ -1,46 +1,46 @@
 [versions]
 # Build / language
-agp = "9.0.1"
-kotlin = "2.3.20"
+agp = "9.2.1"
+kotlin = "2.4.0"
 
 # AndroidX - core / lifecycle / activity / views
-androidxCore = "1.18.0"
+androidxCore = "1.19.0"
 androidxLifecycle = "2.10.0"
 androidxActivity = "1.13.0"
-androidxAppcompat = "1.7.0"
-androidxFragment = "1.8.5"
+androidxAppcompat = "1.7.1"
+androidxFragment = "1.8.9"
 androidxRecyclerview = "1.4.0"
-androidxNavigation = "2.9.0"
+androidxNavigation = "2.9.8"
 
 # Compose (BOM-managed)
-composeBom = "2026.03.01"
+composeBom = "2026.05.01"
 
 # Async / serialization
-coroutines = "1.10.2"
-kotlinxSerialization = "1.8.1"
-kotlinxCollectionsImmutable = "0.3.8"
+coroutines = "1.11.0"
+kotlinxSerialization = "1.11.0"
+kotlinxCollectionsImmutable = "0.5.0"
 
 # DI
-koin = "4.1.0"
+koin = "4.2.1"
 
 # Networking
-ktor = "3.1.3"
+ktor = "3.5.0"
 
 # Image loading
-coil = "3.1.0"
+coil = "3.5.0"
 
 # Logging
 timber = "5.0.1"
 
 # Material Components (Views renderer)
-material = "1.12.0"
+material = "1.14.0"
 
 # Testing
-junitJupiter = "5.11.4"
-junitPlatform = "1.11.4"
-turbine = "1.2.0"
+junitJupiter = "6.1.0"
+junitPlatform = "6.1.0"
+turbine = "1.2.1"
 assertk = "0.28.1"
-mockk = "1.14.3"
+mockk = "1.14.11"
 androidxTestExt = "1.3.0"
 androidxTestRunner = "1.7.0"
 androidxEspresso = "3.7.0"

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.5.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME