chore(cleanup): remove dead Module stubs and unused imports; restore deferred files

Deletes 21 Module.kt scaffolding objects that were never wired into any DI
registry. Removes unused imports across 8 production and 3 test files.

Restores StageExecutor, CyclePolicyResolver, PolicyValidation, and
ReplayContractTest — these are deferred features, not dead code.

infrastructure/artifacts-cas/src/test/kotlin/com/correx/infrastructure/artifactscas/compact/CompactorTest.kt

@@ -18,7 +18,6 @@ import kotlinx.datetime.Clock
 import org.junit.jupiter.api.Assertions.assertArrayEquals
 import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Assertions.assertFalse
-import org.junit.jupiter.api.Assertions.assertNotNull
 import org.junit.jupiter.api.Assertions.assertNull
 import org.junit.jupiter.api.Assertions.assertTrue
 import org.junit.jupiter.api.Test