diff --git a/packages/app/tests/stress/_helpers/content-reset.ts b/packages/app/tests/stress/_helpers/content-reset.ts
new file mode 100644
index 000000000..29aeba3f2
--- /dev/null
+++ b/packages/app/tests/stress/_helpers/content-reset.ts
@@ -0,0 +1,38 @@
+import { readdirSync, rmSync } from 'node:fs';
+import { join } from 'node:path';
+import { REQUIRED_FIXTURE_ENTRY_NAMES } from './fixtures.ts';
+
+async function deletePathIfExists(
+  baseURL: string,
+  kind: 'file' | 'folder',
+  path: string,
+): Promise<void> {
+  const res = await fetch(`${baseURL}/api/delete-path`, {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ kind, path }),
+  });
+  if (res.ok || res.status === 404) return;
+  throw new Error(`delete-path failed for ${kind}:${path}: ${res.status} ${await res.text()}`);
+}
+
+export async function resetContentToFixtureBaseline(
+  baseURL: string,
+  contentDir: string,
+): Promise<void> {
+  const preserved = new Set<string>(REQUIRED_FIXTURE_ENTRY_NAMES);
+  for (const entry of readdirSync(contentDir, { withFileTypes: true })) {
+    if (entry.name.startsWith('.')) continue;
+    if (preserved.has(entry.name)) continue;
+    if (entry.isDirectory()) {
+      await deletePathIfExists(baseURL, 'folder', entry.name);
+      continue;
+    }
+    const docName = entry.name.replace(/\.(md|mdx)$/i, '');
+    if (docName !== entry.name) {
+      await deletePathIfExists(baseURL, 'file', docName);
+      continue;
+    }
+    rmSync(join(contentDir, entry.name), { recursive: true, force: true });
+  }
+}
diff --git a/packages/app/tests/stress/_helpers/index.ts b/packages/app/tests/stress/_helpers/index.ts
index dc53a8314..ae996e2b1 100644
--- a/packages/app/tests/stress/_helpers/index.ts
+++ b/packages/app/tests/stress/_helpers/index.ts
@@ -1,4 +1,5 @@
 export { simulateCopyAndRead, simulateCutAndRead } from './clipboard.ts';
+export { resetContentToFixtureBaseline } from './content-reset.ts';
 export {
   focusEditor,
   selectAllAndWaitForSelection,
diff --git a/packages/app/tests/stress/file-tree-deselect-to-root.e2e.ts b/packages/app/tests/stress/file-tree-deselect-to-root.e2e.ts
index 60b2fa129..f82bc1c6c 100644
--- a/packages/app/tests/stress/file-tree-deselect-to-root.e2e.ts
+++ b/packages/app/tests/stress/file-tree-deselect-to-root.e2e.ts
@@ -12,7 +12,7 @@
  * still lands inside the active folder.
  */
 import type { Page } from '@playwright/test';
-import { expect, test } from './_helpers';
+import { expect, resetContentToFixtureBaseline, test } from './_helpers';
 
 const SIDEBAR = '[data-slot="sidebar-container"]';
 
@@ -50,10 +50,14 @@ async function createFileAndGetDocName(
 }
 
 test.describe('file-tree deselect-to-root', () => {
+  test.beforeEach(async ({ workerServer }) => {
+    await resetContentToFixtureBaseline(workerServer.baseURL, workerServer.contentDir);
+  });
+
   test('empty-space click deselects the row for creation but leaves the editor view', async ({
     page,
     api,
-    baseURL,
+    workerServer,
   }) => {
     await api.seedDocs([
       { name: 'folder/note', markdown: '# Note\n' },
@@ -93,7 +97,7 @@ test.describe('file-tree deselect-to-root', () => {
     await expect(sidebar.getByRole('treeitem', { name: 'note.md', exact: true })).toBeVisible();
     await expect(page).toHaveURL(/folder\/note$/);
 
-    const names = await createFileAndGetDocName(page, baseURL, 'created-at-root');
+    const names = await createFileAndGetDocName(page, workerServer.baseURL, 'created-at-root');
     expect(names).toContain('created-at-root');
     expect(names).not.toContain('folder/created-at-root');
   });
@@ -101,7 +105,7 @@ test.describe('file-tree deselect-to-root', () => {
   test('without the empty-space click, New File still lands in the active folder', async ({
     page,
     api,
-    baseURL,
+    workerServer,
   }) => {
     await api.seedDocs([
       { name: 'folder/note', markdown: '# Note\n' },
@@ -114,7 +118,7 @@ test.describe('file-tree deselect-to-root', () => {
       sidebar.getByRole('treeitem', { name: 'note.md', exact: true, selected: true }),
     ).toBeVisible({ timeout: 20_000 });
 
-    const names = await createFileAndGetDocName(page, baseURL, 'created-in-folder');
+    const names = await createFileAndGetDocName(page, workerServer.baseURL, 'created-in-folder');
     expect(names).toContain('folder/created-in-folder');
     expect(names).not.toContain('created-in-folder');
   });
diff --git a/packages/app/tests/stress/file-tree-drag-to-root.e2e.ts b/packages/app/tests/stress/file-tree-drag-to-root.e2e.ts
index 783e0c3ec..9136ed6ac 100644
--- a/packages/app/tests/stress/file-tree-drag-to-root.e2e.ts
+++ b/packages/app/tests/stress/file-tree-drag-to-root.e2e.ts
@@ -1,5 +1,5 @@
 import type { Page } from '@playwright/test';
-import { expect, test } from './_helpers';
+import { expect, resetContentToFixtureBaseline, test } from './_helpers';
 
 async function dragRowToEmptyRootArea(
   page: Page,
@@ -114,10 +114,14 @@ async function expectDocNames(
 }
 
 test.describe('file-tree drag-to-root (PRD-7043)', () => {
+  test.beforeEach(async ({ workerServer }) => {
+    await resetContentToFixtureBaseline(workerServer.baseURL, workerServer.contentDir);
+  });
+
   test('dropping a nested folder on empty tree space promotes it to the project root', async ({
     page,
     api,
-    baseURL,
+    workerServer,
   }) => {
     await api.seedDocs([
       { name: 'parent/child/note', markdown: '# Note\n\nNested.\n' },
@@ -136,7 +140,10 @@ test.describe('file-tree drag-to-root (PRD-7043)', () => {
 
     await dragRowToEmptyRootArea(page, 'parent/child', true);
 
-    await expectDocNames(page, baseURL, { present: 'child/note', absent: 'parent/child/note' });
+    await expectDocNames(page, workerServer.baseURL, {
+      present: 'child/note',
+      absent: 'parent/child/note',
+    });
 
     await expect(sidebar.getByRole('treeitem', { name: 'child', exact: true })).toBeVisible({
       timeout: 10_000,
@@ -146,7 +153,7 @@ test.describe('file-tree drag-to-root (PRD-7043)', () => {
   test('dropping a nested file on empty tree space promotes it to the project root', async ({
     page,
     api,
-    baseURL,
+    workerServer,
   }) => {
     await api.seedDocs([
       { name: 'folder/note', markdown: '# Note\n\nNested file.\n' },
@@ -165,7 +172,7 @@ test.describe('file-tree drag-to-root (PRD-7043)', () => {
 
     await dragRowToEmptyRootArea(page, 'folder/note', false);
 
-    await expectDocNames(page, baseURL, { present: 'note', absent: 'folder/note' });
+    await expectDocNames(page, workerServer.baseURL, { present: 'note', absent: 'folder/note' });
 
     await expect(sidebar.getByRole('treeitem', { name: 'note.md', exact: true })).toBeVisible({
       timeout: 10_000,