diff --git a/体己/AI/AIRuntime.swift b/体己/AI/AIRuntime.swift
index cdc518a..e061c0f 100644
--- a/体己/AI/AIRuntime.swift
+++ b/体己/AI/AIRuntime.swift
@@ -80,7 +80,9 @@ actor AIRuntime {
                     // session.generate 跨 actor 边界,需要 await
                     let stream = await session.generate(prompt: prompt, maxTokens: maxTokens)
                     for try await chunk in stream {
-                        await self.recordRate(chunk.decodeRate)
+                        // Task 闭包在 generate() 内启动,继承 AIRuntime 的 actor 隔离;
+                        // 调用同 actor 的 recordRate 不需要 await
+                        self.recordRate(chunk.decodeRate)
                         continuation.yield(chunk)
                     }
                     continuation.finish()
diff --git a/体己/AI/ModelStore.swift b/体己/AI/ModelStore.swift
index 06ce918..834db85 100644
--- a/体己/AI/ModelStore.swift
+++ b/体己/AI/ModelStore.swift
@@ -21,8 +21,10 @@ enum ModelKind: String, CaseIterable {
 
 /// `@unchecked Sendable`:rootURL 是 let,方法只读 filesystem(线程安全),
 /// 可被任意 actor / Task 跨边界访问。
+/// `nonisolated(unsafe) shared`:项目开启 `-default-isolation=MainActor` 后
+/// static 默认 MainActor 隔离,跨 actor 访问需要 await。这里手动 opt-out。
 final class ModelStore: @unchecked Sendable {
-    static let shared: ModelStore = {
+    nonisolated(unsafe) static let shared: ModelStore = {
         do {
             let appSupport = try FileManager.default.url(
                 for: .applicationSupportDirectory,
diff --git a/体己/Persistence/FileVault.swift b/体己/Persistence/FileVault.swift
index 0d42634..77c4dc8 100644
--- a/体己/Persistence/FileVault.swift
+++ b/体己/Persistence/FileVault.swift
@@ -10,8 +10,9 @@ enum FileVaultError: Error {
 
 /// `@unchecked Sendable`:rootURL 是 let,方法只 I/O 到沙盒目录(线程安全),
 /// 可被任意 actor / Task 跨边界访问。
+/// `nonisolated(unsafe) shared`:见 ModelStore 同款注释。
 final class FileVault: @unchecked Sendable {
-    static let shared: FileVault = {
+    nonisolated(unsafe) static let shared: FileVault = {
         do {
             let appSupport = try FileManager.default.url(
                 for: .applicationSupportDirectory,