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.

core/config/src/main/kotlin/com/correx/core/config/Module.kt

@@ -1,3 +0,0 @@
-package com.correx.core.config
-
-object Module

core/config/src/test/kotlin/com/correx/core/config/ConfigLoaderTest.kt

@@ -1,8 +1,6 @@
 package com.correx.core.config
 
 import org.junit.jupiter.api.Test
-import java.nio.file.Files
-import java.nio.file.Paths
 import kotlin.test.assertEquals
 
 class ConfigLoaderTest {