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.

build-logic/convention/src/main/kotlin/com/example/architecture/convention/AndroidUnitTestConventionPlugin.kt

@@ -7,11 +7,11 @@ import org.gradle.kotlin.dsl.dependencies
 import org.gradle.kotlin.dsl.withType
 
 /**
- * Runs an Android library module's local unit tests (`src/test`) on the **JUnit 5 platform** with the
+ * Runs an Android library module's local unit tests (`src/test`) on the **JUnit Platform** with the
  * shared `unit-test` toolset (JUnit Jupiter, kotlinx-coroutines-test, Turbine, AssertK).
  *
  * Deliberately does NOT use the `de.mannodermaus.android-junit5` Gradle plugin: its 1.11.x line
- * targets AGP 8.x and we build on AGP 9.0. It isn't needed for *local* unit tests anyway -
+ * targets AGP 8.x and we build on AGP 9.2. It isn't needed for *local* unit tests anyway -
  * `com.android.build.gradle.tasks.factory.AndroidUnitTest` extends Gradle's [Test] task, so calling
  * `useJUnitPlatform()` on it is enough (this mirrors `DomainModuleConventionPlugin`, which does the
  * same for pure-JVM modules).
@@ -21,7 +21,7 @@ class AndroidUnitTestConventionPlugin : Plugin<Project> {
         dependencies {
             add("testImplementation", libs.findBundle("unit-test").get())
             add("testRuntimeOnly", libs.findLibrary("junit-jupiter-engine").get())
-            // Gradle 9 dropped the bundled launcher; JUnit 5 won't start without it.
+            // Gradle 9 dropped the bundled launcher; the JUnit Platform won't start without it.
             add("testRuntimeOnly", libs.findLibrary("junit-platform-launcher").get())
         }
 

build-logic/convention/src/main/kotlin/com/example/architecture/convention/DomainModuleConventionPlugin.kt

@@ -8,7 +8,7 @@ import org.gradle.kotlin.dsl.withType
 
 /**
  * Pure-Kotlin (JVM) module for the domain layer: no Android dependencies. Adds Coroutines (for
- * `Flow`-returning repository interfaces) and runs unit tests on the JUnit 5 platform.
+ * `Flow`-returning repository interfaces) and runs unit tests on the JUnit Platform.
  */
 class DomainModuleConventionPlugin : Plugin<Project> {
     override fun apply(target: Project) = with(target) {
@@ -25,7 +25,7 @@ class DomainModuleConventionPlugin : Plugin<Project> {
             add("testImplementation", libs.findLibrary("mockk").get())
             add("testImplementation", libs.findLibrary("kotlinx-coroutines-test").get())
             add("testRuntimeOnly", libs.findLibrary("junit-jupiter-engine").get())
-            // Gradle 9 dropped the bundled launcher; JUnit 5 won't start without it.
+            // Gradle 9 dropped the bundled launcher; the JUnit Platform won't start without it.
             add("testRuntimeOnly", libs.findLibrary("junit-platform-launcher").get())
         }
 

build-logic/convention/src/main/kotlin/com/example/architecture/convention/ProjectExtensions.kt

@@ -7,7 +7,7 @@ import org.gradle.kotlin.dsl.configure
 import org.gradle.kotlin.dsl.getByType
 import org.jetbrains.kotlin.gradle.dsl.KotlinProjectExtension
 
-internal const val COMPILE_SDK = 36
+internal const val COMPILE_SDK = 37
 internal const val MIN_SDK = 24
 internal const val TARGET_SDK = 36
 internal const val JVM_TARGET = 17