- Migrate build system to Kotlin DSL (build.gradle.kts, settings.gradle.kts)

- Upgrade `compileSdk` and `targetSdk` to 36
- Add German (`de`) localization and string resources
- Add Michachatz F-Droid repository to default list
- Update dependencies and plugins in `libs.versions.toml`
- Remove manual signing configuration from README.md
- Refactor code to use non-deprecated `alpha` property and context-based string retrieval
- Clean up `buildConfig` and locale filtering logic

settings.gradle.kts

@@ -0,0 +1,24 @@
+pluginManagement {
+    repositories {
+        google()
+        mavenCentral()
+        gradlePluginPortal()
+    }
+}
+
+plugins {
+    id("org.gradle.toolchains.foojay-resolver-convention") version "1.0.0"
+}
+
+@Suppress("UnstableApiUsage")
+dependencyResolutionManagement {
+    repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS)
+    repositories {
+        google()
+        mavenCentral()
+        maven { url = uri("https://jitpack.io") }
+    }
+}
+
+rootProject.name = "michas-droid"
+include(":")