docs: restructure domain documentation and update references

Implemented a standardized folder structure for domain documentation to improve clarity and maintainability. Migrated existing files to the new structure, updated links in related documentation, and added README files for navigation and guidance.

docs/02_Reference/Tech_Stack/Gradle_Kotlin_DSL_Primer.md

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+# Gradle Kotlin DSL Primer
+
+**Quelle:** [Original Gradle Documentation](https://docs.gradle.org/current/userguide/kotlin_dsl.html)
+**Kontext:** Dieses Dokument dient als Referenz für die im Projekt verwendete Gradle Kotlin DSL. Es fasst die wichtigsten Konzepte und Syntax-Elemente zusammen.
+
+---
+
+Gradle’s Kotlin DSL offers an alternative to the traditional Groovy DSL, delivering an enhanced editing experience in supported IDEs.
+
+## Key Concepts
+
+### Script File Names
+*   Groovy DSL: `.gradle`
+*   Kotlin DSL: `.gradle.kts`
+
+To activate the Kotlin DSL, use the `.gradle.kts` extension for your build scripts, settings file (`settings.gradle.kts`), and initialization scripts (`init.gradle.kts`).
+
+### Type-safe Model Accessors
+The Kotlin DSL replaces Groovy's dynamic resolution with type-safe model accessors for elements contributed by plugins (configurations, tasks, extensions). This provides better IDE support (code completion, refactoring).
+
+**Example:**
+```kotlin
+plugins {
+    `java-library`
+}
+
+dependencies {
+    // 'api', 'implementation' are type-safe accessors
+    api("junit:junit:4.13")
+    implementation("org.apache.commons:commons-lang3:3.12.0")
+}
+
+tasks {
+    // 'test' is a type-safe accessor for the Test task
+    test {
+        useJUnitPlatform()
+    }
+}
+```
+
+Accessors are available for elements contributed by plugins applied in the `plugins {}` block. For elements created dynamically later in the script, you must fall back to string-based lookups:
+```kotlin
+configurations.create("custom")
+
+dependencies {
+    "custom"("com.google.guava:guava:32.1.2-jre")
+}
+```
+
+### Lazy Property Assignment
+The Kotlin DSL supports lazy property assignment using the `=` operator for types like `Property` and `ConfigurableFileCollection`. This is the preferred way over the `set()` method.
+
+```kotlin
+// Instead of:
+javaVersion.set(JavaLanguageVersion.of(17))
+
+// Use:
+javaVersion = JavaLanguageVersion.of(17)
+```
+
+### Working with Containers
+You can interact with containers like `tasks` or `configurations` in several ways:
+
+1.  **Container API (using `named` and `register`):**
+    ```kotlin
+    tasks.named<Test>("test") {
+        testLogging.showExceptions = true
+    }
+    tasks.register<Copy>("myCopy") {
+        from("source")
+        into("destination")
+    }
+    ```
+
+2.  **Delegated Properties (using `by existing` and `by registering`):**
+    ```kotlin
+    val test by tasks.existing(Test::class) {
+        testLogging.showStackTraces = true
+    }
+    val myCopy by tasks.registering(Copy::class) {
+        from("source")
+        into("destination")
+    }
+    ```
+
+### Extra Properties
+Access project or task-level extra properties via delegated properties:
+```kotlin
+// Define an extra property
+val myNewProperty by extra("initial value")
+
+// Read an existing extra property
+val myExtraProperty: String by extra
+```
+
+### Kotlin DSL Plugin (`kotlin-dsl`)
+This plugin is essential for developing build logic in Kotlin (e.g., in `buildSrc` or for convention plugins). It automatically applies the Kotlin plugin and adds necessary dependencies like `kotlin-stdlib` and `gradleKotlinDsl()`.
+
+```kotlin
+// buildSrc/build.gradle.kts
+plugins {
+    `kotlin-dsl`
+}
+
+repositories {
+    mavenCentral()
+}
+```
+
+*(Dies ist eine gekürzte Zusammenfassung. Das Originaldokument enthält detailliertere Informationen.)*