refactor(protocol): add toolName to ToolResult, remove proto typealiases, rename id→toolCallId, drop Conversation.events()

Three protocol-level changes from Android-client review (items 1-3, 5-6):

1) toolName denormalization in ToolResult (3 layers):
   - :outbox-api/Event.ToolResult: +toolName: String? = null
   - :journal-api/MessageRecord.ToolResult: +toolName: String? = null
   - :proto/Message.ToolResult: +toolName: String? = null
   - :storage-ksqlite, :journal-ksqlite ResultPayload codec: +toolName
   - :standalone/ToolDispatcher, ConversationLoop: thread toolName = call.name
   Nullable + default = backward-compat for already-persisted histories
   and existing clients.

2) Drop proto/Event.kt, AgentEvent.kt, CommonEvent.kt typealiases.
   is proto.Event.End failed with 'Unresolved reference End' (alias
   loses nested-class access). Use pw.binom.agentik.outbox.{Event,
   AgentEvent, CommonEvent} directly everywhere — :proto already has
   api(:outbox-api), the package is visible to consumers, no shim
   needed. 21 files rewired, 3 files deleted.

3) Rename Event.ToolResult.id → toolCallId (option B per user).
   In :outbox-api Event.ToolResult.id == Event.ToolCall.id (one value,
   one name); the persistent journal keeps MessageRecord.ToolResult.id
   as its own PK + toolCallId as FK to the call — different semantics,
   left untouched. Fixed ToolDispatcher bug: emitted id = resultId
   while KDoc claimed id == ToolCall.id; now emits toolCallId = callId.

4) Remove Conversation.events() from :proto; OutboxStore is sole event source.
   Conversation is a pure per-conversation abstraction (send/getMessages/
   rename/close). Live events only via agent.outbox.conversationEvents/
   agentEvents/events. HTTP route /conversations/{id}/events stays for
   wire-compat but routes through outbox internally (map { it.event }).

jvmTest green (95 tasks).

journal-api/src/commonMain/kotlin/pw/binom/agentik/journal/MessageRecord.kt

@@ -55,6 +55,14 @@ sealed interface MessageRecord {
         override val id: String,
         override val conversationId: String,
         val toolCallId: String,
+        /**
+         * Имя тула, денормализованное из соответствующего `MessageRecord.ToolCall.toolName`.
+         * Денормализация экономна (одна строка в SQLite) и снимает с UI
+         * необходимость сопоставления `toolCallId → toolName`. `null` —
+         * безопасный backfill для записей до миграции или для сиротливых
+         * результатов без предшествующего `ToolCall`.
+         */
+        val toolName: String? = null,
         val result: String?,
         override val createdAt: Instant,
     ) : MessageRecord