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.

apps/server/src/test/kotlin/com/correx/apps/server/bridge/DomainEventMapperTest.kt

@@ -35,7 +35,6 @@ import com.correx.core.events.types.ToolInvocationId
 import com.correx.core.events.types.TransitionId
 import com.correx.core.events.types.ValidationReportId
 import com.correx.core.inference.TokenUsage
-import kotlinx.datetime.Clock
 import kotlinx.datetime.Instant
 import kotlinx.coroutines.test.runTest
 import org.junit.jupiter.api.Assertions.assertEquals