refactor: split composeApp to client and ui

also renamed client.datasource to client.data, which made me realise
.gitignore was ignoring `data` and therefore some gtfsr source files
😭

client/build.gradle.kts

@@ -0,0 +1,55 @@
+import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+
+plugins {
+    alias(libs.plugins.kotlinMultiplatform)
+    alias(libs.plugins.kotlinSerialization)
+    alias(libs.plugins.androidLibrary)
+}
+
+kotlin {
+    androidTarget {
+        @OptIn(ExperimentalKotlinGradlePluginApi::class)
+        compilerOptions {
+            jvmTarget.set(JvmTarget.JVM_11)
+        }
+    }
+
+    compilerOptions {
+        freeCompilerArgs.add("-opt-in=kotlin.time.ExperimentalTime")
+    }
+
+    iosX64()
+    iosArm64()
+    iosSimulatorArm64()
+
+    sourceSets {
+        androidMain.dependencies {
+            implementation(libs.compose.ui.tooling.preview)
+            implementation(libs.androidx.activity.compose)
+            implementation(libs.kotlinx.coroutines.android)
+            implementation(libs.play.services.location)
+        }
+        commonMain.dependencies {
+            implementation(libs.koin.core)
+            implementation(libs.kotlinx.coroutines.core)
+            implementation(libs.kotlinx.datetime)
+            implementation(libs.ktor.client.core)
+            implementation(libs.ktor.client.contentnegotiation)
+            implementation(libs.ktor.serialization.kotlinx.json)
+            implementation(projects.shared)
+        }
+    }
+}
+
+android {
+    namespace = "moe.lava.banksia.client"
+    compileSdk = libs.versions.android.compileSdk.get().toInt()
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
+    defaultConfig {
+        minSdk = libs.versions.android.minSdk.get().toInt()
+    }
+}