remove :message-store-api and migrate functionality to :journal-api and :reflection-api

- Removed `:message-store-api` module and associated classes (ConversationStore, ReflectionStore, Ids, etc.).
- Migrated reusable components to `:journal-api` (conversation-related) and `:reflection-api` (reflection-related).
- Updated imports and module dependencies across all projects to reflect new structure.
- Adjusted build scripts and tests for compatibility with the new APIs.

standalone/build.gradle.kts

@@ -41,10 +41,10 @@ kotlin {
         commonMain.dependencies {
             implementation(project(":proto"))
             implementation(project(":server"))
-            implementation(project(":message-store-api"))
             implementation(project(":journal-api"))
             implementation(project(":outbox-api"))
             implementation(project(":context-api"))
+            implementation(project(":reflection-api"))
 
             // Commons
             implementation(libs.kotlinx.coroutines.core)
@@ -67,10 +67,10 @@ kotlin {
             if (!skipVectorMemory) {
                 implementation(project(":memory-vector"))
             }
-            implementation(project(":message-store-api"))
             implementation(project(":journal-api"))
             implementation(project(":outbox-api"))
             implementation(project(":context-api"))
+            implementation(project(":reflection-api"))
             implementation(project(":storage-ksqlite"))
 
             // Новый единый канал событий агента — заменил старые