diff --git a/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md b/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md
index c5459a51..f8cf002d 100644
--- a/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md
+++ b/design/10-review/process/16-mnote-web-runtime-module-maintainability-checklist-v1.md
@@ -208,7 +208,7 @@ cargo test --manifest-path rust/Cargo.toml -p mnote-web --lib ssr::pages::layout
 - [x] D2. `tree-shell-page-runtime.js`：page tree keyboard、expand、focus、drag/drop intent。
 - [x] D3. `tree-shell-filetree-runtime.js`：filetree row normalization、resource meta、open target。
 - [x] D4. `tree-shell-picker-runtime.js`：picker search/focus/pick root。
-- [ ] D5. `tree-shell-dom-runtime.js`：DOM patch/render helpers。
+- [x] D5. `tree-shell-dom-runtime.js`：DOM patch/render helpers。
 - [x] D6. `tree-shell-icons-runtime.js`：icon templates 和 resource kind badge。
 - [ ] D7. entrypoint 少于 2,500 行。
 
diff --git a/rust/crates/mnote-web/browser/tree-shell-dom-runtime.js b/rust/crates/mnote-web/browser/tree-shell-dom-runtime.js
new file mode 100644
index 00000000..0e3bc0e8
--- /dev/null
+++ b/rust/crates/mnote-web/browser/tree-shell-dom-runtime.js
@@ -0,0 +1,137 @@
+// MNote debug /tree shell DOM patch and hydration helpers.
+
+export function patchTreeShellPageActiveDom(context) {
+  if (context.mode !== "page") return;
+  context.appElement.querySelectorAll('[data-rust-rendered-row="page"]').forEach((row) => {
+    if (!(row instanceof HTMLElement)) return;
+    const nodeId = context.normalizeText(row.dataset.nodeId);
+    const isFocused = nodeId === context.focusedNodeId;
+    row.dataset.active = String(nodeId === context.currentActiveDocumentId);
+    row.dataset.focused = String(isFocused);
+    row.tabIndex = isFocused ? 0 : -1;
+    row.dataset.dropFeedback = String(context.activePageDropNodeId === nodeId);
+  });
+}
+
+export function patchTreeShellPageExpansionDom(context, nodeId) {
+  if (context.mode !== "page") return false;
+  const normalizedNodeId = context.normalizeText(nodeId);
+  if (!normalizedNodeId) return false;
+  const item = context.itemById.get(normalizedNodeId);
+  if (!item) return false;
+  const nodeElement = context.appElement.querySelector(
+    `.tree-node[data-node-id="${CSS.escape(normalizedNodeId)}"]`,
+  );
+  if (!(nodeElement instanceof HTMLElement)) return false;
+  const row = nodeElement.querySelector(
+    `:scope > .tree-row[data-node-id="${CSS.escape(normalizedNodeId)}"]`,
+  );
+  const children = context.getSiblings(normalizedNodeId);
+  const hasChildren = item.childCount > 0 && children.length > 0;
+  const isExpanded = hasChildren && context.expanded.has(normalizedNodeId);
+  if (row instanceof HTMLElement) {
+    row.setAttribute("aria-expanded", hasChildren ? String(isExpanded) : "false");
+    const toggleButton = row.querySelector('[data-testid="tree-node-toggle"]');
+    if (toggleButton instanceof HTMLButtonElement) {
+      toggleButton.textContent = isExpanded ? "▾" : "▸";
+      toggleButton.setAttribute(
+        "aria-label",
+        `${isExpanded ? "折叠" : "展开"} ${item.title}`,
+      );
+    }
+  }
+  if (!hasChildren) {
+    context.patchPageTreeActiveDom();
+    return true;
+  }
+  let childrenList = Array.from(nodeElement.children).find(
+    (child) => child instanceof HTMLElement && child.classList.contains("tree-children"),
+  );
+  if (isExpanded) {
+    if (!(childrenList instanceof HTMLElement)) {
+      childrenList = document.createElement("ul");
+      childrenList.className = "tree-children";
+      children.forEach((child) => {
+        childrenList.appendChild(context.renderNode(child));
+      });
+      nodeElement.appendChild(childrenList);
+    }
+    childrenList.hidden = false;
+    childrenList.style.display = "";
+  } else if (childrenList instanceof HTMLElement) {
+    childrenList.hidden = true;
+    childrenList.style.display = "none";
+  }
+  context.patchPageTreeActiveDom();
+  return true;
+}
+
+export function hydrateTreeShellInitialPageTree(context) {
+  if (context.mode !== "page") return false;
+  const root = context.appElement.querySelector('[data-rust-page-renderer="initial_v1"]');
+  if (!(root instanceof HTMLElement)) {
+    return false;
+  }
+  root.querySelectorAll('[data-rust-rendered-row="page"]').forEach((row) => {
+    if (!(row instanceof HTMLElement)) return;
+    const nodeId = context.normalizeText(row.dataset.nodeId);
+    const item = context.itemById.get(nodeId);
+    if (!item) return;
+    context.bindPageRowEvents(row, item);
+  });
+  if (context.focusedNodeId) {
+    context.focusRowElement(context.focusedNodeId);
+  }
+  return true;
+}
+
+export function focusTreeShellPickerRowElement(context, pickerItemKey) {
+  const normalizedItemKey = context.normalizeText(pickerItemKey);
+  window.requestAnimationFrame(() => {
+    const row =
+      normalizedItemKey === "__root__"
+        ? context.appElement.querySelector('[data-rust-rendered-row="picker-root"]')
+        : context.appElement.querySelector(
+            `.tree-row[data-node-id="${CSS.escape(normalizedItemKey)}"]`,
+          );
+    if (!(row instanceof HTMLElement)) return;
+    row.focus({ preventScroll: true });
+    row.scrollIntoView({ block: "nearest" });
+  });
+}
+
+export function patchTreeShellPickerActiveDom(context) {
+  if (context.mode !== "picker") return;
+  context.appElement
+    .querySelectorAll('[data-rust-rendered-row="picker"], [data-rust-rendered-row="picker-root"]')
+    .forEach((row) => {
+      if (!(row instanceof HTMLElement)) return;
+      const nodeId = context.normalizeText(row.dataset.nodeId);
+      const isRoot = row.dataset.rustRenderedRow === "picker-root";
+      const isFocused = isRoot
+        ? context.currentActivePickerItemKey === "__root__"
+        : context.currentActivePickerItemKey === nodeId ||
+          (!context.currentActivePickerItemKey && context.currentActiveDocumentId === nodeId);
+      row.dataset.focused = String(isFocused);
+      row.tabIndex = isFocused ? 0 : -1;
+    });
+}
+
+export function hydrateTreeShellInitialPickerTree(context) {
+  if (context.mode !== "picker") return false;
+  const root = context.appElement.querySelector('[data-rust-picker-renderer="initial_v1"]');
+  if (!(root instanceof HTMLElement)) {
+    return false;
+  }
+  root.querySelectorAll('[data-rust-rendered-row="picker-root"]').forEach((row) => {
+    context.bindPickerRootEvents(row);
+  });
+  root.querySelectorAll('[data-rust-rendered-row="picker"]').forEach((row) => {
+    if (!(row instanceof HTMLElement)) return;
+    const nodeId = context.normalizeText(row.dataset.nodeId);
+    const item = context.itemById.get(nodeId);
+    if (!item) return;
+    context.bindPickerRowEvents(row, item);
+  });
+  return true;
+}
diff --git a/rust/crates/mnote-web/browser/tree-shell-runtime.js b/rust/crates/mnote-web/browser/tree-shell-runtime.js
index 539d24d8..741fa4e1 100644
--- a/rust/crates/mnote-web/browser/tree-shell-runtime.js
+++ b/rust/crates/mnote-web/browser/tree-shell-runtime.js
@@ -20,6 +20,14 @@ import {
   getFileTreeRowOwnerDocumentId,
   normalizeTreeShellTreeItems,
 } from "./tree-shell-filetree-runtime.js";
+import {
+  focusTreeShellPickerRowElement,
+  hydrateTreeShellInitialPageTree,
+  hydrateTreeShellInitialPickerTree,
+  patchTreeShellPageActiveDom,
+  patchTreeShellPageExpansionDom,
+  patchTreeShellPickerActiveDom,
+} from "./tree-shell-dom-runtime.js";
 import {
   computeTreeShellPickerStateActionResult,
   getTreeShellVisiblePickerEntries,
@@ -2943,90 +2951,38 @@ function startTreeShellRuntime() {
     });
   };
 
-  const patchPageTreeActiveDom = () => {
-    if (mode !== "page") return;
-    appElement.querySelectorAll('[data-rust-rendered-row="page"]').forEach((row) => {
-      if (!(row instanceof HTMLElement)) return;
-      const nodeId = normalizeText(row.dataset.nodeId);
-      const isFocused = nodeId === focusedNodeId;
-      row.dataset.active = String(nodeId === currentActiveDocumentId);
-      row.dataset.focused = String(isFocused);
-      row.tabIndex = isFocused ? 0 : -1;
-      row.dataset.dropFeedback = String(activePageDropNodeId === nodeId);
+  const patchPageTreeActiveDom = () =>
+    patchTreeShellPageActiveDom({
+      mode,
+      appElement,
+      normalizeText,
+      focusedNodeId,
+      currentActiveDocumentId,
+      activePageDropNodeId,
     });
-  };
 
-  const patchPageTreeExpansionDom = (nodeId) => {
-    if (mode !== "page") return false;
-    const normalizedNodeId = normalizeText(nodeId);
-    if (!normalizedNodeId) return false;
-    const item = itemById.get(normalizedNodeId);
-    if (!item) return false;
-    const nodeElement = appElement.querySelector(
-      `.tree-node[data-node-id="${CSS.escape(normalizedNodeId)}"]`,
-    );
-    if (!(nodeElement instanceof HTMLElement)) return false;
-    const row = nodeElement.querySelector(
-      `:scope > .tree-row[data-node-id="${CSS.escape(normalizedNodeId)}"]`,
-    );
-    const children = getSiblings(normalizedNodeId);
-    const hasChildren = item.childCount > 0 && children.length > 0;
-    const isExpanded = hasChildren && expanded.has(normalizedNodeId);
-    if (row instanceof HTMLElement) {
-      row.setAttribute("aria-expanded", hasChildren ? String(isExpanded) : "false");
-      const toggleButton = row.querySelector('[data-testid="tree-node-toggle"]');
-      if (toggleButton instanceof HTMLButtonElement) {
-        toggleButton.textContent = isExpanded ? "▾" : "▸";
-        toggleButton.setAttribute(
-          "aria-label",
-          `${isExpanded ? "折叠" : "展开"} ${item.title}`,
-        );
-      }
-    }
-    if (!hasChildren) {
-      patchPageTreeActiveDom();
-      return true;
-    }
-    let childrenList = Array.from(nodeElement.children).find(
-      (child) => child instanceof HTMLElement && child.classList.contains("tree-children"),
-    );
-    if (isExpanded) {
-      if (!(childrenList instanceof HTMLElement)) {
-        childrenList = document.createElement("ul");
-        childrenList.className = "tree-children";
-        children.forEach((child) => {
-          childrenList.appendChild(renderNode(child));
-        });
-        nodeElement.appendChild(childrenList);
-      }
-      childrenList.hidden = false;
-      childrenList.style.display = "";
-    } else if (childrenList instanceof HTMLElement) {
-      childrenList.hidden = true;
-      childrenList.style.display = "none";
-    }
-    patchPageTreeActiveDom();
-    return true;
-  };
+  const patchPageTreeExpansionDom = (nodeId) =>
+    patchTreeShellPageExpansionDom({
+      mode,
+      appElement,
+      normalizeText,
+      itemById,
+      expanded,
+      getSiblings,
+      renderNode,
+      patchPageTreeActiveDom,
+    }, nodeId);
 
-  const hydrateInitialPageTree = () => {
-    if (mode !== "page") return false;
-    const root = appElement.querySelector('[data-rust-page-renderer="initial_v1"]');
-    if (!(root instanceof HTMLElement)) {
-      return false;
-    }
-    root.querySelectorAll('[data-rust-rendered-row="page"]').forEach((row) => {
-      if (!(row instanceof HTMLElement)) return;
-      const nodeId = normalizeText(row.dataset.nodeId);
-      const item = itemById.get(nodeId);
-      if (!item) return;
-      bindPageRowEvents(row, item);
+  const hydrateInitialPageTree = () =>
+    hydrateTreeShellInitialPageTree({
+      mode,
+      appElement,
+      normalizeText,
+      itemById,
+      bindPageRowEvents,
+      focusedNodeId,
+      focusRowElement,
     });
-    if (focusedNodeId) {
-      focusRowElement(focusedNodeId);
-    }
-    return true;
-  };
 
   const syncFileTreeSelectionDom = () => {
     if (mode !== "filetree") return;
@@ -3333,56 +3289,30 @@ function startTreeShellRuntime() {
     });
   };
 
-  const focusPickerRowElement = (pickerItemKey) => {
-    const normalizedItemKey = normalizeText(pickerItemKey);
-    window.requestAnimationFrame(() => {
-      const row =
-        normalizedItemKey === "__root__"
-          ? appElement.querySelector('[data-rust-rendered-row="picker-root"]')
-          : appElement.querySelector(
-              `.tree-row[data-node-id="${CSS.escape(normalizedItemKey)}"]`,
-            );
-      if (!(row instanceof HTMLElement)) return;
-      row.focus({ preventScroll: true });
-      row.scrollIntoView({ block: "nearest" });
-    });
-  };
+  const focusPickerRowElement = (pickerItemKey) =>
+    focusTreeShellPickerRowElement({
+      appElement,
+      normalizeText,
+    }, pickerItemKey);
 
-  const patchPickerActiveDom = () => {
-    if (mode !== "picker") return;
-    appElement
-      .querySelectorAll('[data-rust-rendered-row="picker"], [data-rust-rendered-row="picker-root"]')
-      .forEach((row) => {
-        if (!(row instanceof HTMLElement)) return;
-        const nodeId = normalizeText(row.dataset.nodeId);
-        const isRoot = row.dataset.rustRenderedRow === "picker-root";
-        const isFocused = isRoot
-          ? currentActivePickerItemKey === "__root__"
-          : currentActivePickerItemKey === nodeId ||
-            (!currentActivePickerItemKey && currentActiveDocumentId === nodeId);
-        row.dataset.focused = String(isFocused);
-        row.tabIndex = isFocused ? 0 : -1;
-      });
-  };
+  const patchPickerActiveDom = () =>
+    patchTreeShellPickerActiveDom({
+      mode,
+      appElement,
+      normalizeText,
+      currentActivePickerItemKey,
+      currentActiveDocumentId,
+    });
 
-  const hydrateInitialPickerTree = () => {
-    if (mode !== "picker") return false;
-    const root = appElement.querySelector('[data-rust-picker-renderer="initial_v1"]');
-    if (!(root instanceof HTMLElement)) {
-      return false;
-    }
-    root.querySelectorAll('[data-rust-rendered-row="picker-root"]').forEach((row) => {
-      bindPickerRootEvents(row);
+  const hydrateInitialPickerTree = () =>
+    hydrateTreeShellInitialPickerTree({
+      mode,
+      appElement,
+      normalizeText,
+      itemById,
+      bindPickerRootEvents,
+      bindPickerRowEvents,
     });
-    root.querySelectorAll('[data-rust-rendered-row="picker"]').forEach((row) => {
-      if (!(row instanceof HTMLElement)) return;
-      const nodeId = normalizeText(row.dataset.nodeId);
-      const item = itemById.get(nodeId);
-      if (!item) return;
-      bindPickerRowEvents(row, item);
-    });
-    return true;
-  };
 
   const hydrateInitialRenderer = () => {
     if (mode === "page") {
diff --git a/rust/crates/mnote-web/src/routes/mod.rs b/rust/crates/mnote-web/src/routes/mod.rs
index cdf2e9b3..b761bd8c 100644
--- a/rust/crates/mnote-web/src/routes/mod.rs
+++ b/rust/crates/mnote-web/src/routes/mod.rs
@@ -186,6 +186,10 @@ pub fn build_router(state: AppState) -> Router {
             "/api/mnote-browser-runtime/tree-shell-picker-runtime.js",
             get(web_shell::tree_shell_picker_runtime_asset),
         )
+        .route(
+            "/api/mnote-browser-runtime/tree-shell-dom-runtime.js",
+            get(web_shell::tree_shell_dom_runtime_asset),
+        )
         .route(
             "/api/mnote-browser-runtime/document-conflict-panel-runtime.js",
             get(web_shell::document_conflict_panel_runtime_asset),
@@ -642,6 +646,7 @@ mod tests {
             "/api/mnote-browser-runtime/tree-shell-icons-runtime.js",
             "/api/mnote-browser-runtime/tree-shell-filetree-runtime.js",
             "/api/mnote-browser-runtime/tree-shell-picker-runtime.js",
+            "/api/mnote-browser-runtime/tree-shell-dom-runtime.js",
             "/api/mnote-browser-runtime/document-conflict-panel-runtime.js",
             "/api/mnote-browser-runtime/document-pane-runtime.js",
             "/api/mnote-browser-runtime/document-mindmap-host-runtime.js",
diff --git a/rust/crates/mnote-web/src/routes/web_shell.rs b/rust/crates/mnote-web/src/routes/web_shell.rs
index 95976076..8211bd2d 100644
--- a/rust/crates/mnote-web/src/routes/web_shell.rs
+++ b/rust/crates/mnote-web/src/routes/web_shell.rs
@@ -1008,6 +1008,20 @@ pub async fn tree_shell_picker_runtime_asset() -> Response {
         .unwrap_or_else(|_| Response::new(Body::empty()))
 }
 
+pub async fn tree_shell_dom_runtime_asset() -> Response {
+    const JS: &str = include_str!("../../browser/tree-shell-dom-runtime.js");
+    Response::builder()
+        .status(StatusCode::OK)
+        .header(
+            header::CONTENT_TYPE,
+            "application/javascript; charset=utf-8",
+        )
+        .header(header::CACHE_CONTROL, "no-store")
+        .header(HEADER_MNOTE_WEB_OWNER, "mnote-web")
+        .body(Body::from(JS))
+        .unwrap_or_else(|_| Response::new(Body::empty()))
+}
+
 pub async fn document_conflict_panel_runtime_asset() -> Response {
     // include_str! 路径相对于当前源文件 (src/routes/web_shell.rs -> ../../browser/)
     const JS: &str = include_str!("../../browser/document-conflict-panel-runtime.js");