refactor: rename the router subsystem to Talkie

The 'router' name was misleading — it's the always-on conversational front-end
(CHAT triage + STEERING into a running workflow), not a routing layer, and it's
distinct from InferenceRouter. Rename core:router -> core:talkie, package
com.correx.core.router -> com.correx.core.talkie, and RouterFacade/Config/State/
Repository/ContextBuilder/Projector/Reducer/Response -> Talkie*. Config section
[router] -> [talkie] (legacy [router] still read as fallback).

Persisted wire formats are preserved: ChatTurnRole.ROUTER and the
RouterNarrationEvent @SerialName("RouterNarration") stay, so existing event
logs still replay. RouterNarrationEvent the class is now TalkieNarrationEvent.

infrastructure/build.gradle

@@ -7,7 +7,7 @@ plugins {
 dependencies {
     implementation project(":core:tools")
     implementation project(":core:events")
-    implementation project(":core:router")
+    implementation project(":core:talkie")
     implementation project(":core:inference")
     implementation project(":core:approvals")
     implementation project(":core:sessions")