Use proper Gradle Property injection + extract tasks into classes

- SettingsExtension: abstract class with @Inject, Property<String>, Property<Boolean>
- Conventions set after creation (outputDir, autoGenerate)
- Extract ContextTask and CleanTask into task/ package
- SettingsPlugin is now thin — just registers tasks
- Matches wrkx architecture pattern

Author: ClankerGuru

build.gradle.kts

@@ -3,8 +3,7 @@ plugins {
 }
 
 dependencies {
-    compileOnly("org.jetbrains.kotlin:kotlin-compiler-embeddable:2.1.20")
-    testImplementation("org.jetbrains.kotlin:kotlin-compiler-embeddable:2.1.20")
+    implementation("org.jetbrains.kotlin:kotlin-compiler-embeddable:2.1.20")
 }
 
 gradlePlugin {

src/main/kotlin/zone/clanker/gradle/srcx/Srcx.kt

@@ -12,7 +12,7 @@ import org.gradle.api.initialization.Settings
  * }
  *
  * srcx {
- *     outputDir = ".srcx"
+ *     outputDir.set(".srcx")
  * }
  * ```
  *