diff --git a/apps/ai-game-creator-shell/src-tauri/src/project/write_lock.rs b/apps/ai-game-creator-shell/src-tauri/src/project/write_lock.rs
index f615b2ddb..9ed36a8a9 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/project/write_lock.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/project/write_lock.rs
@@ -860,14 +860,11 @@ pub(crate) fn acquire_project_write_lock_failure(
                         }
                     }
                 }
-                if crate::agent::autonomous_game_build_root_run_active_at(root)
-                    && project_write_lock_is_owned_by_current_process(&path)
-                {
-                    // The autonomous game-build lane intentionally permits
-                    // parallel specialist actions.  If the durable lock belongs
-                    // to this very process, contention is an in-process overlap,
-                    // not another application editing the project.  Return an
-                    // advisory guard and leave the real lock untouched.
+                if project_write_lock_is_owned_by_current_process(&path) {
+                    // A project lock is the client-use lock.  Nested calls in
+                    // the same client process must reuse that ownership instead
+                    // of waiting on their own durable marker.  Cross-process
+                    // contenders still take the normal retryable path.
                     return Ok(ProjectWriteLock {
                         path,
                         content: String::new(),
diff --git a/apps/ai-game-creator-shell/src-tauri/src/tests/project_tools.rs b/apps/ai-game-creator-shell/src-tauri/src/tests/project_tools.rs
index bd77f59e6..b109e7995 100644
--- a/apps/ai-game-creator-shell/src-tauri/src/tests/project_tools.rs
+++ b/apps/ai-game-creator-shell/src-tauri/src/tests/project_tools.rs
@@ -5611,12 +5611,14 @@ fn local_project_checkpoint_diff_restore_and_index_are_recorded() {
 }
 
 #[test]
-fn project_write_lock_rejects_parallel_writer_and_releases_on_drop() {
+fn project_write_lock_reuses_same_process_owner_and_releases_on_drop() {
     let root = unique_project_path();
     let first = acquire_project_write_lock(&root, "file.write").expect("first lock");
 
-    let error = acquire_project_write_lock(&root, "file.delete").expect_err("second lock fails");
-    assert!(error.contains("项目正在被其他写操作占用"));
+    let nested = acquire_project_write_lock(&root, "file.delete")
+        .expect("same process must reuse the client project lock");
+    drop(nested);
+    assert!(root.join(PROJECT_WRITE_LOCK_PATH).exists());
 
     drop(first);
     acquire_project_write_lock(&root, "file.delete").expect("lock released");
diff --git a/docs/project-memory/plans/【实施计划】项目客户端占用锁收敛-2026-09-14.md b/docs/project-memory/plans/【实施计划】项目客户端占用锁收敛-2026-09-14.md
new file mode 100644
index 000000000..f1ffb1b07
--- /dev/null
+++ b/docs/project-memory/plans/【实施计划】项目客户端占用锁收敛-2026-09-14.md
@@ -0,0 +1,34 @@
+# 【实施计划】项目客户端占用锁收敛-2026-09-14
+
+Version: 1
+Status: in-progress
+Date: 2026-09-14
+Milestone: `【里程碑】项目客户端占用锁收敛-2026-09-14.md`
+
+## 代码边界
+
+- `apps/ai-game-creator-shell/src-tauri/src/project/write_lock.rs`
+- `apps/ai-game-creator-shell/src-tauri/src/runner/project_owner.rs`
+- `apps/ai-game-creator-shell/src-tauri/src/runner/protocol.rs`
+- 锁恢复、Runtime 写入和 Runner owner 定向测试
+
+## 修改顺序
+
+1. 统一同进程嵌套调用的项目锁语义，禁止自等待。
+2. 盘点并迁移 Runner 的项目级 owner 文件到统一锁，保留诊断投影与跨 boot 恢复。
+3. 删除重复项目级锁路径及其专属调用，保留底层原子写和 Git 锁。
+4. 补齐同进程重入、跨进程占用、崩溃恢复和锁释放测试。
+
+## 验证命令
+
+- `cargo fmt --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml -- --check`
+- `cargo test --manifest-path apps/ai-game-creator-shell/src-tauri/Cargo.toml project_write_lock_reuses_same_process_owner_and_releases_on_drop --no-default-features`
+- Runner owner 与 response stream 相关定向测试
+- `npm run check:encoding`
+- `git diff --check`
+
+## 风险与回滚点
+
+- Runner 与 GUI 可能是不同进程；统一锁前必须验证同一客户端不会互相阻塞。
+- 旧 `.agent/runtime/execution-owner.lock` 残留需要按 PID/启动身份安全回收，不能直接删除。
+- 若跨 boot 恢复或 GUI/Runner 联动回归，回滚统一路径迁移，保留已验证的同进程重入修复。
diff --git a/docs/project-memory/plans/【里程碑】项目客户端占用锁收敛-2026-09-14.md b/docs/project-memory/plans/【里程碑】项目客户端占用锁收敛-2026-09-14.md
new file mode 100644
index 000000000..ed1c643a2
--- /dev/null
+++ b/docs/project-memory/plans/【里程碑】项目客户端占用锁收敛-2026-09-14.md
@@ -0,0 +1,28 @@
+# 【里程碑】项目客户端占用锁收敛-2026-09-14
+
+Version: 1
+Status: in-progress
+Date: 2026-09-14
+Parent Spec: `docs/technical/【技术方案】AI游戏创作智能体App实施计划-2026-06-24.md`
+
+## 目标
+
+项目只保留一个面向客户端占用的项目级跨进程锁，防止多个客户端同时打开同一项目；同一客户端进程内的嵌套调用复用既有项目锁，不因自身持锁进入等待。
+
+## 边界
+
+- 项目客户端占用锁与项目写入调用的职责统一，跨进程竞争仍返回占用语义。
+- Agent DB、session lane、manifest 原子写和 Git 自身的底层一致性机制不在本里程碑删除范围内。
+- 不改变项目 revision、权限、幂等、恢复和数据格式合同。
+
+## 验收标准
+
+- 同一进程内嵌套取得项目锁立即返回 advisory guard，不等待、不删除真实持有者锁。
+- 不同进程持有项目锁时仍保持占用失败与残留回收判据。
+- 客户端项目占用入口与 Runtime 写入入口不会各自维护第二个项目级锁文件。
+- 锁释放后下一客户端可重新取得锁。
+- 定向 Rust 锁测试、`cargo fmt --check`、`npm run check:encoding`、`git diff --check` 通过。
+
+## 未决事项
+
+- Runner 的 `execution-owner.lock` 如何迁移到统一客户端占用锁，需要补充跨进程启动、恢复和诊断测试后再落地。
diff --git a/docs/technical/【技术方案】AI游戏创作智能体App实施计划-2026-06-24.md b/docs/technical/【技术方案】AI游戏创作智能体App实施计划-2026-06-24.md
index fd13ced6e..48f5be252 100644
--- a/docs/technical/【技术方案】AI游戏创作智能体App实施计划-2026-06-24.md
+++ b/docs/technical/【技术方案】AI游戏创作智能体App实施计划-2026-06-24.md
@@ -1363,3 +1363,8 @@ DirectProject 使用 `approvalPolicy=never`，避免每次原生调用再经过
 - **成功后行为**：重读 manifest，**不切换版本**（没有新版本可切），**不自动重载 / 重启运行中的预览**（PRD §3.2 末条），不做运行时资源重映射。可见变化只有资源卡「当前使用」高亮移到替换素材、`@` 面板「当前版本素材」更新。
 - **已知代价（用户已确认接受）**：**替换历史不可回溯**——替换前身份只剩那条审计与 manifest 的 `.previous` 副本；需要"某版本历史上换过什么"时要另立切片（PRD §3.2 / §5.3 保留为未来合同正是为此）。
 - **验证**：绑定改写通道定向 7 条（`project/manifest/version_binding_rewrite_tests.rs`）+ 替换定向 8 条 + `shared-contracts` 20 条。**变异验证**：① 去掉「未放行版本整条相等」→ 两周转红；② 放行集合改成整个版本数组 → 「未放行版本」转红；③ 去掉长度检查 → 「不增不删」转红；④ 准入删掉 category → 硬门禁与候选两条转红；另有 ⑤ 改回"原地改既有版本但绕过放行口"→ 被「项目版本记录写入后不可修改、删除或重排」拦下。前端 13 条（模型 9 + 真链路 4）。AGC 全量 1231 passed / 4 skipped / 0 failed；共享美术画布组件 1385 passed；`npm run ai-game-creator-shell:typecheck`（含 check-config）、`cargo check --locked --all-targets`、`npm run check:encoding`、`git diff --check` 全绿。`/api/external/v1`、SpacetimeDB schema、`packages/shared` 与 `shared-contracts` 的 wire DTO、manifest 结构、布局 sidecar schema 均未改动。
+
+## 2026-09-14 项目客户端占用锁收敛
+
+项目锁职责收敛为“客户端占用项目”这一事实：同一客户端进程内的嵌套项目写入调用复用已有项目锁并返回 advisory guard，不再等待自身持有的 `.agent/project.lock`；跨进程竞争继续沿用现有占用、残留回收和权限分类。Runner 的 `.agent/runtime/execution-owner.lock` 迁移到统一项目占用锁仍属于进行中的里程碑，完成前不改变其恢复诊断合同。
+