refactor: externalize local folder watch marker

design/03-rust-web/process/3-20-browser-runtime-followup-checklist-v1.md

@@ -181,3 +181,7 @@ UI / 浏览器可见项必须有真实浏览器截图或结构化 smoke 证据
   - 边界：未改 `refreshLocalFolderSidebarSnapshot` 的 fetch URL、projection JSON 渲染主路径、watcher 标记、focus/selection/sidebar shell 副作用；不把 HTML snapshot 应用重新接入主刷新流程。
   - Worker C 验证：`git diff --check`、`node --check rust/crates/mnote-web/browser/filetree-runtime.js`、`cargo fmt --manifest-path rust/Cargo.toml --all --check`、`cargo check --manifest-path rust/Cargo.toml -p mnote-web`、`cargo test --manifest-path rust/Cargo.toml -p mnote-web filetree_runtime -- --test-threads=1` 通过。
   - Worker D smoke：Reasonix run `reasonix-2026-05-24T22-26-26-122Z-62733e93` 有完整 handoff/result/截图且源码零 diff；`task487-local-folder-tree-live-consumer-smoke.js` 在 3001 通过，PageTree/FileTree 外部创建/删除均为 `treeLiveApplied=resync`，导航数为 0。
+- 2026-05-25：Batch AB 未派发 Reasonix worker；Codex 主控完成 `refreshLocalFolderSidebarSnapshot` 内部 watch projection 标记的小切片。
+  - 修改：`filetree-runtime.js` 新增并导出 `markLocalFolderWatchApplied(value)`；`layout.rs` 的同名 wrapper 优先委托 runtime，inline fallback 保留 `data-mnote-local-folder-watch-applied="projection"` 行为。
+  - 边界：未改 projection fetch URL、JSON 渲染、selection/focus/sidebar shell 副作用、附件存在性刷新、tree live SSE consumer；本批只外置刷新完成证据标记。
+  - 已验证：`node --check rust/crates/mnote-web/browser/filetree-runtime.js`、`git diff --check`、`cargo fmt --manifest-path rust/Cargo.toml --all --check`、`cargo check --manifest-path rust/Cargo.toml -p mnote-web`、`cargo test --manifest-path rust/Cargo.toml -p mnote-web filetree_runtime -- --test-threads=1`。

rust/crates/mnote-web/browser/filetree-runtime.js

@@ -239,6 +239,13 @@ function applyLocalFolderSidebarSnapshot(nextDocument, options) {
   return applied;
 }
 
+function markLocalFolderWatchApplied(value) {
+  var appliedValue = String(value || 'projection');
+  if (!document || !document.documentElement) return false;
+  document.documentElement.setAttribute('data-mnote-local-folder-watch-applied', appliedValue);
+  return true;
+}
+
 function revealFileTreeRow(row) {
   if (!(row instanceof HTMLElement)) return;
   var node = row.closest('.tree-node');
@@ -378,6 +385,7 @@ window.__mnoteFileTreeRuntime = {
   groupRowsByParent: groupRowsByParent,
   replaceSidebarTreeFromDocument: replaceSidebarTreeFromDocument,
   applyLocalFolderSidebarSnapshot: applyLocalFolderSidebarSnapshot,
+  markLocalFolderWatchApplied: markLocalFolderWatchApplied,
   fileTreeRowKind: fileTreeRowKind,
   fileTreeRowDocumentId: fileTreeRowDocumentId,
   fileTreeRowAssetId: fileTreeRowAssetId,

rust/crates/mnote-web/src/ssr/pages/layout.rs

@@ -2442,6 +2442,14 @@ const SIDEBAR_TREE_JS: &str = r##"
     return applied;
   }
 
+  function markLocalFolderWatchApplied(value) {
+    var runtimeFn = fileTreeRuntimeFunction('markLocalFolderWatchApplied');
+    if (runtimeFn) return runtimeFn(value);
+    var appliedValue = String(value || 'projection');
+    document.documentElement.setAttribute('data-mnote-local-folder-watch-applied', appliedValue);
+    return true;
+  }
+
   async function refreshLocalFolderSidebarSnapshot() {
     var workspaceId = currentWorkspaceId();
     var rootUri = currentRootUri();
@@ -2474,7 +2482,7 @@ const SIDEBAR_TREE_JS: &str = r##"
     schedulePendingLocalFolderRestoreFocus();
     restoreSidebarTreeTab();
     refreshEditorLocalAttachmentExistence();
-    document.documentElement.setAttribute('data-mnote-local-folder-watch-applied', 'projection');
+    markLocalFolderWatchApplied('projection');
     return true;
   }
 
@@ -11111,6 +11119,7 @@ mod tests {
         assert!(
             SIDEBAR_TREE_JS.contains("fileTreeRuntimeFunction('applyLocalFolderSidebarSnapshot')")
         );
+        assert!(SIDEBAR_TREE_JS.contains("fileTreeRuntimeFunction('markLocalFolderWatchApplied')"));
         let document_id_body = js_function_body(SIDEBAR_TREE_JS, "fileTreeRowDocumentId");
         assert!(
             document_id_body.contains("data-document-id")
@@ -11131,6 +11140,12 @@ mod tests {
                 && apply_body.contains("replaceSidebarTreeFromDocument(nextDocument, fileRootId)"),
             "inline fallback 必须保留 sidebar/page tree DOM 应用行为"
         );
+        let watch_applied_body = js_function_body(SIDEBAR_TREE_JS, "markLocalFolderWatchApplied");
+        assert!(
+            watch_applied_body.contains("data-mnote-local-folder-watch-applied")
+                && watch_applied_body.contains("String(value || 'projection')"),
+            "inline fallback 必须保留 local folder watch projection 标记"
+        );
     }
 
     #[test]
@@ -11161,12 +11176,15 @@ mod tests {
         assert!(FILETREE_RUNTIME_JS.contains("function groupRowsByParent"));
         assert!(FILETREE_RUNTIME_JS.contains("function replaceSidebarTreeFromDocument"));
         assert!(FILETREE_RUNTIME_JS.contains("function applyLocalFolderSidebarSnapshot"));
+        assert!(FILETREE_RUNTIME_JS.contains("function markLocalFolderWatchApplied"));
         assert!(FILETREE_RUNTIME_JS.contains("appendUploadedAssetRow: appendUploadedAssetRow"));
         assert!(FILETREE_RUNTIME_JS.contains("groupRowsByParent: groupRowsByParent"));
         assert!(FILETREE_RUNTIME_JS
             .contains("replaceSidebarTreeFromDocument: replaceSidebarTreeFromDocument"));
         assert!(FILETREE_RUNTIME_JS
             .contains("applyLocalFolderSidebarSnapshot: applyLocalFolderSidebarSnapshot"));
+        assert!(FILETREE_RUNTIME_JS
+            .contains("markLocalFolderWatchApplied: markLocalFolderWatchApplied"));
         assert!(FILETREE_RUNTIME_JS
             .contains("uploadIntent: String(detail.uploadIntent || 'filetree.folder.drop')"));
         assert!(FILETREE_RUNTIME_JS