feat(client): client-side caching for conversation list via agent.outbox events

Adds `agent.conversationStore` (read-only view on `conversation` table) to
the :proto Agent interface, plus `agent.renameConversation(id, title?)`
command. Client-side cache in :client is built from a snapshot
(`remote.listFlow(0)` → `local.upsert(...)`) + live updates via
`outbox.agentEvents()` (Created/Deleted/Renamed/Touched).

Changes:
- :journal-api — split `ConversationStore` (read-only: get/list) and
  `MutableConversationStore` (CRUD: upsert/delete/rename/touch);
  `ConversationStore` gained `listFlow` (cold-flow paging via `list`).
- :outbox-api — `AgentEvent.Touched(date, id, updatedAt)` event so
  client cache stays fresh after `send()` (which bumps `updatedAt`).
- :proto.Agent — added `conversationStore: ConversationStore` property,
  added `renameConversation(id, title?): Instant?` command, removed
  `getConversations(offset, limit)` (now: `conversationStore.list(...)`).
- :server — `GET /conversations` now returns `List<ConversationRecord>`
  (lightweight metadata, no handle/image-support flags); `PATCH
  /conversations/{id}` uses `agent.renameConversation` and returns
  the updated `ConversationRecord`.
- :journal-inmemory — expanded targets to jvm+macos+linux+mingw (matches
  :client); moved `InMemoryMutableConversationStore` here from
  :storage-inmemory so :client can use it without pulling ios targets.
- :storage-inmemory — depends on :journal-inmemory.
- :storage-ksqlite — pre-staged rename `KsqliteConversationStore` →
  `KsqliteMutableConversationStore` to match the new interface split.
- :standalone — `ChatAgent` exposes `conversationStore` as a read-only
  view of its `mutableConversationStore`; emits `AgentEvent.Touched`
  after each `send()` (after `conversationStore.touch(id, ts)`).
- :client — new `HttpConversationStore` (read-only HTTP impl);
  `AgentikAgent` wraps the agent with `wrapWithLocalConversationCache`
  so the client sees an in-memory cache (snapshot + outbox events)
  instead of direct HTTP. Cache scope + HttpClient + background job
  all cancelled in `agent.close()`.
- :client/README — new «Кэш списка бесед» section with the
  `listFlow → upsert` / `agentEvents → apply` pattern and a note that
  `conversationStore` is read-only (writes only via Agent commands).

All 96 jvmTest tasks green.

storage-ksqlite/src/commonMain/kotlin/pw/binom/agentik/storage/ksqlite/KsqliteMutableConversationStore.kt

@@ -3,7 +3,7 @@ package pw.binom.agentik.storage.ksqlite
 import kotlin.time.Clock
 import kotlin.time.Instant
 import pw.binom.agentik.journal.ConversationRecord
-import pw.binom.agentik.journal.ConversationStore
+import pw.binom.agentik.journal.MutableConversationStore
 import pw.binom.db.ksqlite.SQLiteConnection
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.sync.Mutex
@@ -11,15 +11,15 @@ import kotlinx.coroutines.sync.withLock
 import kotlinx.coroutines.withContext
 
 /**
- * ksqlite-реализация [ConversationStore]. Схема таблицы `conversation` живёт
+ * ksqlite-реализация [MutableConversationStore]. Схема таблицы `conversation` живёт
  * в [Schema] (миграция через PRAGMA user_version) — этот класс только
  * готовит и выполняет SQL, ссылаясь на `Schema.COL_*` / `Schema.TABLE_*`.
  */
-class KsqliteConversationStore(
+class KsqliteMutableConversationStore(
     private val connection: SQLiteConnection,
     private val messageStore: KsqliteMessageStore? = null,
     private val workingMemoryStore: KsqliteWorkingMemoryStore? = null,
-) : ConversationStore {
+) : MutableConversationStore {
 
     private val mutex = Mutex()
 

storage-ksqlite/src/commonMain/kotlin/pw/binom/agentik/storage/ksqlite/KsqliteStores.kt

@@ -2,7 +2,7 @@ package pw.binom.agentik.storage.ksqlite
 
 import pw.binom.agentik.context.ContextStore
 import pw.binom.agentik.journal.MutableJournalStore
-import pw.binom.agentik.journal.ConversationStore
+import pw.binom.agentik.journal.MutableConversationStore
 import pw.binom.agentik.reflection.ReflectionStore
 import pw.binom.db.ksqlite.SQLiteConnection
 
@@ -17,7 +17,7 @@ import pw.binom.db.ksqlite.SQLiteConnection
  */
 class KsqliteStores internal constructor(
     val connection: SQLiteConnection,
-    val conversations: ConversationStore,
+    val conversations: MutableConversationStore,
     val messages: MutableJournalStore,
     val workingMemory: ContextStore,
     val reflections: ReflectionStore,
@@ -51,7 +51,7 @@ class KsqliteStores internal constructor(
             val working = KsqliteWorkingMemoryStore(conn)
             return KsqliteStores(
                 connection = conn,
-                conversations = KsqliteConversationStore(conn, messages, working),
+                conversations = KsqliteMutableConversationStore(conn, messages, working),
                 messages = messages,
                 workingMemory = working,
                 reflections = KsqliteReflectionStore(conn),

storage-ksqlite/src/commonTest/kotlin/pw/binom/agentik/storage/ksqlite/KsqliteMutableConversationStoreTest.kt

@@ -12,7 +12,7 @@ import kotlin.test.assertTrue
 import kotlin.time.Duration
 import kotlin.time.Instant
 
-class KsqliteConversationStoreTest {
+class KsqliteMutableConversationStoreTest {
     private lateinit var stores: KsqliteStores
 
     @BeforeTest

storage-ksqlite/src/commonTest/kotlin/pw/binom/agentik/storage/ksqlite/SchemaMigrationTest.kt

@@ -79,7 +79,7 @@ class SchemaMigrationTest {
         // constructor internal, тест в том же модуле и может его звать.
         val stores = KsqliteStores(
             connection = conn,
-            conversations = KsqliteConversationStore(conn),
+            conversations = KsqliteMutableConversationStore(conn),
             messages = KsqliteMessageStore(conn),
             workingMemory = KsqliteWorkingMemoryStore(conn),
             reflections = KsqliteReflectionStore(conn),