新增: Phase3 EventBus Value载荷+桥接层

- EventBus 载荷改 serde_json::Value(D2 全19变体透传),删 AiBusEvent 强类型子集
- 新增 publish_event(AiChatEvent) helper(内部 to_value→publish,供 emit 双写)
- 新增 remote_bridge.rs 桥接层(MiniCommand→Tauri command 路由+R1 同conv并发兜底)
- agentic/mod.rs 11处 AiBusEvent→AiChatEvent 迁移(Error/Completed/Round)

src-tauri/src/commands/ai/mod.rs

@@ -37,6 +37,7 @@ pub mod http;
 pub mod knowledge_inject;
 pub mod prompt;
 pub mod provider_pool;
+pub mod remote_bridge;
 pub mod secret;
 pub mod skills;
 pub mod stream_recv;