feat(journal-ksqlite): add :journal-ksqlite module with KsqliteJournalStore implementation

- Introduced a new `:journal-ksqlite` module implementing `:journal-api` with Ksqlite backend.
- Added a minimal schema (message table + 1 index) for append-only audit logs, eliminating modifications and ensuring immutable storage.
- Provides `KsqliteJournalStore` for appending, listing, and clearing messages with JSON-encoded payloads.
- Autonomous schema migration (`Schema.migrate`) and in-memory tests validate functionality.
- Partial duplication of `:storage-ksqlite/KsqliteMessageStore`; consumers will transition gradually.

journal-ksqlite/build.gradle.kts

@@ -0,0 +1,33 @@
+plugins {
+    alias(libs.plugins.kotlin.multiplatform)
+    alias(libs.plugins.kotlin.serialization)
+}
+
+// KMP-реализация :journal-api (JournalStore / MutableJournalStore) поверх ksqlite.
+// Минимальная — только таблица `message` для append-only audit log'а.
+// ConversationStore / ReflectionStore / WorkingMemoryStore живут в своих
+// собственных ksqlite-модулях.
+//
+// Цели сборки — jvm() + linuxX64() + mingwX64(); Apple targets auto-disabled
+// на Linux (см. KDoc :storage-ksqlite).
+
+kotlin {
+    jvmToolchain(21)
+
+    jvm()
+    linuxX64()
+    mingwX64()
+
+    sourceSets {
+        commonMain.dependencies {
+            implementation("pw.binom.db:ksqlite:0.1.1-SNAPSHOT")
+            implementation(libs.kotlinx.serialization.json)
+
+            api(project(":journal-api"))
+        }
+        commonTest.dependencies {
+            implementation(kotlin("test"))
+            implementation(libs.kotlinx.coroutines.test)
+        }
+    }
+}