prepare linuxX64: switch to kotlin.uuid.Uuid and ktor-server-cio

1. UUID: java.util.UUID.randomUUID() → commonMain helper Ids.new(prefix)
   wrapping kotlin.uuid.Uuid.random().  kotlin.uuid is stdlib (KMP: jvm +
   all native targets), so the call sites (ChatAgent, ChatConversation,
   SqliteWorkingMemoryStore) are now ready for native builds.  Format kept:
   '<prefix>-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'.

2. HTTP engine: ktor-server-netty → ktor-server-cio.  Netty is JVM-only;
   CIO is KMP (jvm, linuxX64, ios, etc.) and feature-complete for our
   needs (POST + SSE).  standalone/build.gradle.kts drops netty and adds
   cio; Main.kt imports io.ktor.server.cio.CIO and calls
   embeddedServer(CIO, port = port).

Netty is left in libs.versions.toml (catalog entry kept) in case anyone
needs to fall back; only :standalone stopped depending on it.

E2E verified end-to-end against litellm local/codding: standalone-1.0.0
tarball starts on AGENTIK_PORT, GET /health -> 'ok', POST
/agentik/conversations -> 201 with new UUID-format id, POST .../messages
returns real LLM answer ('Ассистент').  44/44 unit tests green.

standalone/build.gradle.kts

@@ -48,9 +48,11 @@ kotlin {
             implementation(libs.sqldelight.sqlite.driver)
 
             // Ktor server (для :server facade + a2aServer)
+            // Используем CIO вместо Netty — он KMP (jvm + linuxX64/ios/...), нам нужен
+            // для будущей native-сборки; на JVM работает идентично для нашего сценария.
             implementation(libs.ktor.server.core)
             implementation(libs.ktor.server.sse)
-            implementation(libs.ktor.server.netty)
+            implementation(libs.ktor.server.cio)
             implementation(libs.ktor.server.content.negotiation)
             implementation(libs.ktor.serialization.kotlinx.json)