diff --git a/apps/ai-game-creator-shell/src-tauri/src/project/filesystem.rs b/apps/ai-game-creator-shell/src-tauri/src/project/filesystem.rs
index 8c140b94b..566f41128 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/project/filesystem.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/project/filesystem.rs
@@ -415,12 +415,15 @@ pub(crate) fn should_skip_project_snapshot_path(relative_path: &str) -> bool {
 /// 这些文件能从项目源码重跑出来，不该进索引、checkpoint 或版本库视角，也不该被当成项目变更；
 /// 但 Agent 必须能写它们，所以不能并进 `should_skip_project_snapshot_path`——那份列表同时是
 /// `agc_apply_patch` 的写入门禁，并进去会让首次适配直接卡死。
+///
+/// `.export` 只认项目根那一层（`EXPORT_WORK_RELATIVE_DIR` 就是 `root/.export`）：源码里合法的
+/// 嵌套目录 `game/.export/...` 是用户自己的文件，不能被误伤。
 pub(crate) fn should_skip_project_derived_path(relative_path: &str) -> bool {
     project_snapshot_path_is_excluded(relative_path, false)
         || relative_path
             .split('/')
-            .filter(|component| !component.is_empty())
-            .any(|component| {
+            .find(|component| !component.is_empty())
+            .is_some_and(|component| {
                 PROJECT_DERIVED_EXCLUDED_COMPONENTS
                     .iter()
                     .any(|candidate| component.eq_ignore_ascii_case(candidate))
@@ -439,7 +442,8 @@ pub(crate) fn should_skip_project_derived_path(relative_path: &str) -> bool {
  * `.env*` 与凭据类文件名一律不参与同步；符号链接与重解析点在扫描阶段单独跳过。
  *
  * 另外，同步还多认 `PROJECT_DERIVED_EXCLUDED_COMPONENTS`（`.export`）：本机派生
- * 的导出工作目录不进同步，但 Agent 仍要能读写它。
+ * 的导出工作目录不进同步，但 Agent 仍要能读写它。`.export` 同样只认项目根那一层，
+ * 源码里的嵌套 `game/.export/...` 不在此列。
  */
 pub(crate) fn should_skip_project_snapshot_sync_path(relative_path: &str) -> bool {
     project_snapshot_path_is_excluded(relative_path, true)
@@ -536,8 +540,8 @@ fn project_snapshot_path_is_excluded(relative_path: &str, include_agent_state: b
             && !(include_agent_state && component == ".agent")
     }) || (include_agent_state
         && components
-            .iter()
-            .any(|component| PROJECT_DERIVED_EXCLUDED_COMPONENTS.contains(&component.as_str())))
+            .first()
+            .is_some_and(|component| PROJECT_DERIVED_EXCLUDED_COMPONENTS.contains(&component.as_str())))
     {
         return true;
     }
diff --git a/apps/ai-game-creator-shell/src-tauri/src/project_snapshot/tests.rs b/apps/ai-game-creator-shell/src-tauri/src/project_snapshot/tests.rs
index 7008d2eee..f344b9e82 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/project_snapshot/tests.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/project_snapshot/tests.rs
@@ -267,6 +267,41 @@ fn project_snapshot_sync_policy_keeps_agent_state_and_still_blocks_credentials()
     assert!(!should_skip_project_index_path("game/main.ts"));
 }
 
+#[test]
+fn derived_export_directory_is_matched_only_at_the_project_root() {
+    // 项目根的 `.export` 才是本机派生工作目录：数据视角与快照同步都排除。
+    for root_export in [
+        ".export/xhs-minitool.zip",
+        ".export/xhs-minitool.json",
+        ".EXPORT/xhs-minitool.zip",
+    ] {
+        assert!(
+            should_skip_project_derived_path(root_export),
+            "根目录的 .export 必须排除：{root_export}"
+        );
+        assert!(
+            should_skip_project_snapshot_sync_path(root_export),
+            "根目录的 .export 不进快照同步：{root_export}"
+        );
+    }
+
+    // 嵌套在源码目录里的 `.export` 是用户自己的文件，不能按本机派生目录误伤。
+    for nested in [
+        "game/.export/local.ts",
+        "game/.export/xhs-minitool.zip",
+        "src/vendor/.export/keep.json",
+    ] {
+        assert!(
+            !should_skip_project_derived_path(nested),
+            "嵌套 .export 是用户源码，不该被数据视角排除：{nested}"
+        );
+        assert!(
+            !should_skip_project_snapshot_sync_path(nested),
+            "嵌套 .export 是用户源码，不该被排除出快照同步：{nested}"
+        );
+    }
+}
+
 #[test]
 fn project_snapshot_diff_reuses_metadata_and_reports_a_single_modification() {
     let root = fixture_root();