diff --git a/e2e/tests/helpers/hub.js b/e2e/tests/helpers/hub.js
index 8421bbf5..5c904e15 100644
--- a/e2e/tests/helpers/hub.js
+++ b/e2e/tests/helpers/hub.js
@@ -1,28 +1,31 @@
-// Shared E2E helpers for the Hub UI (PRs #800/#801; f023f89 "no-rail layout").
+// Shared E2E helpers for the Hub UI.
 //
-// Since the hub landed, bare '/' no longer boots the editor: it renders the
-// HomeView library page (data-testid="home-view"), and the editor is reached by
-// clicking "New diagram" (home-empty-new — empty-library CTA) or the header New
-// button (home-new). The Sidebar icon rail was removed app-wide (f023f89), so
-// nothing navigates via sidebar-* anymore. Editor URLs (/?id= or ?code=/?embed)
-// still render their surface directly without passing through the hub.
+// Editor-as-landing (2026-06-13): bare '/' boots the EDITOR again (resume
+// last-code, else seed a sample diagram), so '/' renders data-testid="dsl-editor"
+// directly. The HomeView library page (data-testid="home-view") is now OPT-IN via
+// '/?view=diagrams'. The Sidebar icon rail was removed app-wide (f023f89), so
+// nothing navigates via sidebar-* anymore. Editor deep links (/?id= or ?code=/
+// ?embed) still render their surface directly.
 //
 // Every spec that needs the editor goes through openEditor(); specs that need
-// the library grid go through gotoHome(). Keeping the click-through in ONE place
-// means the next hub-routing change is a one-file fix.
+// the library grid go through gotoHome() — which navigates to '/?view=diagrams'.
+// Keeping the routing in ONE place means the next routing change is a one-file fix.
 
 import { expect } from '@playwright/test';
 
 const HOME_VIEW = '[data-testid="home-view"]';
 const EDITOR_SURFACE = '[data-testid="dsl-editor"] .cm-content';
 
+// The hub/library is opt-in via this query param under editor-as-landing.
+export const HUB_URL = '/?view=diagrams';
+
 /**
  * Navigate to `url` (default '/') and end up in the editor.
  *
- * - If the URL renders the HomeView hub, click through its New CTA
- *   (home-empty-new when the library is empty, else home-new).
- * - If the URL renders the editor directly (e.g. '/?id=…' or '/?code=…'),
- *   just wait for the editor surface.
+ * - If the URL renders the editor directly (the default for bare '/', and for
+ *   '/?id=…' or '/?code=…'), just wait for the editor surface.
+ * - If the URL renders the HomeView hub ('/?view=diagrams'), click through its
+ *   New CTA (home-empty-new when the library is empty, else home-new).
  *
  * React renders after the 'load' event page.goto resolves on, so we first wait
  * for WHICHEVER surface this URL produces (home-view or the CM6 editor) before
@@ -32,7 +35,9 @@ export async function openEditor(page, { url = '/' } = {}) {
   await page.goto(url);
   const homeView = page.locator(HOME_VIEW);
   const editorSurface = page.locator(EDITOR_SURFACE);
-  await expect(homeView.or(editorSurface).first()).toBeVisible({ timeout: 15_000 });
+  await expect(homeView.or(editorSurface).first()).toBeVisible({
+    timeout: 15_000,
+  });
   if (await homeView.isVisible()) {
     const emptyCta = page.locator('[data-testid="home-empty-new"]');
     if (await emptyCta.isVisible()) {
@@ -45,13 +50,15 @@ export async function openEditor(page, { url = '/' } = {}) {
 }
 
 /**
- * Navigate to the HomeView library page ('/').
+ * Navigate to the HomeView library page ('/?view=diagrams').
  *
- * A FULL navigation (not client-side breadcrumb) so the signed-out useItems
- * mount re-reads the localItems index from a clean slate — robust regardless of
- * whether the in-page subscription has caught up.
+ * Editor-as-landing: the hub is opt-in via ?view=diagrams; bare '/' now boots
+ * the editor, so the library is reached only by this param. A FULL navigation
+ * (not a client-side breadcrumb) so the signed-out useItems mount re-reads the
+ * localItems index from a clean slate — robust regardless of whether the in-page
+ * subscription has caught up.
  */
 export async function gotoHome(page) {
-  await page.goto('/');
+  await page.goto(HUB_URL);
   await expect(page.locator(HOME_VIEW)).toBeVisible({ timeout: 15_000 });
 }
diff --git a/e2e/tests/library.spec.js b/e2e/tests/library.spec.js
index 7d20dc2e..d41be22e 100644
--- a/e2e/tests/library.spec.js
+++ b/e2e/tests/library.spec.js
@@ -1,8 +1,9 @@
 // M03 Task 15 — Library E2E (signed-out / local flows only).
 //
-// Hub (PRs #800/#801; f023f89 "no-rail layout"): the in-editor Library PANEL was
-// retired — the Sidebar icon rail (sidebar-library) and LibraryPanel no longer
-// render anywhere. The web library IS the HomeView page at '/': rows are
+// f023f89 "no-rail layout": the in-editor Library PANEL was retired — the
+// Sidebar icon rail (sidebar-library) and LibraryPanel no longer render anywhere.
+// The web library IS the HomeView page, reached at '/?view=diagrams' under
+// editor-as-landing (2026-06-13; bare '/' boots the editor again). Rows are
 // home-card-<id> cards in home-grid, search is home-search (same SearchInput
 // component, so the clear affordance is still search-clear), and the bulk
 // Export-all / Import controls (lib-export-all / lib-import-input) were re-homed
@@ -21,10 +22,10 @@
 // /create-share reads the cloud item doc + needs a fresh ID token). Same auth
 // note as persistence.spec.js / M02.
 //
-// Navigation note: seeding happens in the EDITOR (reached through the hub's New
-// CTA — openEditor); reading the library back happens by a FULL navigation to
-// '/' (gotoHome), which freshly mounts useItems and re-reads the localItems
-// index regardless of in-page subscription timing.
+// Navigation note: seeding happens in the EDITOR (bare '/' boots it directly
+// under editor-as-landing — openEditor); reading the library back happens by a
+// FULL navigation to '/?view=diagrams' (gotoHome), which freshly mounts useItems
+// and re-reads the localItems index regardless of in-page subscription timing.
 
 import { test, expect } from '@playwright/test';
 import { suppressOneTimeModals } from './helpers/onetime';
@@ -62,8 +63,8 @@ async function gotoFresh(page) {
   await suppressOneTimeModals(page);
   await page.goto('/');
   await page.evaluate(() => localStorage.clear());
-  // Hub: '/' is the HomeView library — seeding drives the editor's header, so
-  // click through the hub's New CTA (empty library → home-empty-new).
+  // Editor-as-landing: bare '/' boots the editor (cleared storage → seeds a fresh
+  // sample diagram), so openEditor lands straight on the CM6 surface here.
   await openEditor(page);
 }
 
@@ -134,10 +135,11 @@ async function seedItem(page, { title, dsl, firstSave = false }) {
 }
 
 /**
- * Navigate to the library. Hub (PRs #800/#801): the library is no longer an
- * in-editor side panel (sidebar-library + library-panel are gone — f023f89
- * removed the rail and LibraryPanel was retired); it is the HomeView page at
- * '/'. gotoHome is a FULL navigation, so useItems freshly re-reads the
+ * Navigate to the library. The library is no longer an in-editor side panel
+ * (sidebar-library + library-panel are gone — f023f89 removed the rail and
+ * LibraryPanel was retired); it is the HomeView page. Editor-as-landing
+ * (2026-06-13): the hub moved off bare '/' and is now opt-in at '/?view=diagrams'.
+ * gotoHome navigates there (a FULL navigation), so useItems freshly re-reads the
  * localItems index — same guarantee the old reload-then-open-panel shape gave.
  */
 async function reloadIntoLibrary(page) {
@@ -147,7 +149,9 @@ async function reloadIntoLibrary(page) {
 // ──────────────────────────────────────────────────────────────────────────────
 // Test 1: Library lists locally-saved diagrams; search filters them.
 // ──────────────────────────────────────────────────────────────────────────────
-test('library lists local items and SearchInput filters them', async ({ page }) => {
+test('library lists local items and SearchInput filters them', async ({
+  page,
+}) => {
   page.on('pageerror', (err) => {
     if (isThirdPartyError(err)) return;
     throw err;
@@ -177,7 +181,9 @@ test('library lists local items and SearchInput filters them', async ({ page })
 
   // Both saved items appear as cards in the home grid (hub PRs: library-list /
   // lib-row-* became home-grid / home-card-* — see HomeView.tsx + DiagramCard.tsx).
-  await expect(page.locator('[data-testid="home-grid"]')).toBeVisible({ timeout: 10_000 });
+  await expect(page.locator('[data-testid="home-grid"]')).toBeVisible({
+    timeout: 10_000,
+  });
   await expect(page.getByText('AlphaDiagram', { exact: true })).toBeVisible();
   await expect(page.getByText('GammaDiagram', { exact: true })).toBeVisible();
 
@@ -219,7 +225,9 @@ test('export-all triggers a JSON file download', async ({ page }) => {
   });
 
   await reloadIntoLibrary(page);
-  await expect(page.getByText('ExportableDiagram', { exact: true })).toBeVisible();
+  await expect(
+    page.getByText('ExportableDiagram', { exact: true }),
+  ).toBeVisible();
 
   // Clicking export-all builds a Blob and triggers a download (handleExportAll →
   // downloadText('zenuml-diagrams.json', …)). Assert the download event fires.
@@ -251,7 +259,9 @@ test('importing a JSON file adds a new library row', async ({ page }) => {
   });
 
   await reloadIntoLibrary(page);
-  await expect(page.getByText('PreexistingDiagram', { exact: true })).toBeVisible();
+  await expect(
+    page.getByText('PreexistingDiagram', { exact: true }),
+  ).toBeVisible();
 
   // Build a minimal import payload matching the { items: Item[] } shape that
   // exportAllItemsJson produces and parseImportJson accepts. The migrate step
@@ -288,6 +298,10 @@ test('importing a JSON file adds a new library row', async ({ page }) => {
   // regardless of in-page subscription timing.
   await reloadIntoLibrary(page);
 
-  await expect(page.getByText('ImportedDiagram', { exact: true })).toBeVisible();
-  await expect(page.getByText('PreexistingDiagram', { exact: true })).toBeVisible();
+  await expect(
+    page.getByText('ImportedDiagram', { exact: true }),
+  ).toBeVisible();
+  await expect(
+    page.getByText('PreexistingDiagram', { exact: true }),
+  ).toBeVisible();
 });
diff --git a/e2e/tests/persistence.spec.js b/e2e/tests/persistence.spec.js
index 0531b00f..4ef6ff7c 100644
--- a/e2e/tests/persistence.spec.js
+++ b/e2e/tests/persistence.spec.js
@@ -3,14 +3,14 @@
 //
 // Tests the local-persistence layer (localStorage) that survives page reloads
 // and across tabs — without any Firebase auth:
-//   1. typed DSL survives a reload of the editor URL (hub re-ground — see test 1)
+//   1. typed DSL survives a reload of the editor URL (last-code restore — see test 1)
 //   2. per-page content is isolated across multi-page tabs
 //   3. "New" resets to the default starter DSL
 //
-// Hub (PRs #800/#801): bare '/' renders the HomeView library, so every test
-// reaches the editor through the hub's New CTA (openEditor) and the editor lives
-// at /?id=<uuid>. That URL shape changes WHICH boot branch a reload exercises —
-// see the test-1 comment.
+// Editor-as-landing (2026-06-13): bare '/' boots the EDITOR directly (no ?id),
+// so every test reaches the editor via openEditor() landing straight on '/'. A
+// reload of bare '/' re-enters the boot resolver, which (with preserveLastCode,
+// default true) reads localStorage['code'] back into the editor — see test 1.
 
 import { test, expect } from '@playwright/test';
 import { suppressOneTimeModals } from './helpers/onetime';
@@ -60,9 +60,9 @@ async function gotoFresh(page) {
   // Step 1: land on the app origin so we can write to its localStorage.
   await page.goto('/');
   await page.evaluate(() => localStorage.clear());
-  // Step 2: hub (PRs #800/#801) — '/' is the HomeView library; reach the editor
-  // through the New CTA. User data is empty; the init script re-seeds only the
-  // one-time flags. We do NOT re-clear here.
+  // Step 2: editor-as-landing — bare '/' boots the editor directly. With storage
+  // cleared, boot seeds a fresh sample diagram; openEditor lands on the CM6
+  // surface. The init script re-seeds only the one-time flags. We do NOT re-clear.
   await openEditor(page);
 }
 
@@ -82,21 +82,26 @@ function editorLocator(page) {
 }
 
 // ──────────────────────────────────────────────────────────────────────────────
-// Test 1: Typed DSL survives a page reload of the editor URL.
+// Test 1: Typed DSL survives a page reload of the editor URL (last-code restore).
 //
-// HUB RE-GROUND (PRs #800/#801) — this used to be "last-code restore": reload at
-// '/' booted the preserveLastCode branch, which read localStorage['code'] back
-// into the editor. Under the hub the editor lives at /?id=<uuid> and bare '/'
-// renders the HomeView library, so the boot-time last-code READ branch
-// (resolveBootItem branch 3 — only reachable with NO ?id) can no longer be hit
-// from any editor URL on the web (verified live: reloading /?id= with an unsaved
-// item boots 'new' → starter DSL). The reload-persistence contract the user sees
-// is now: SAVE the diagram → reload /?id=<id> → boot getItem(id) restores the
-// local copy. This test follows that contract; the still-live last-code WRITE
-// path (visibilitychange/beforeunload → 'code' slot, REQ-PST) keeps its
-// assertion below so a regression in the write side stays visible.
+// EDITOR-AS-LANDING RE-GROUND (2026-06-13): bare '/' boots the EDITOR directly,
+// and with preserveLastCode (default true) a reload of '/' re-enters the boot
+// resolver's last-code branch (resolveBootItem branch 3) — reading
+// localStorage['code'] back into the editor. This reinstates the original
+// last-code-restore contract that the interim hub layout had displaced (under the
+// hub bare '/' rendered the library, so that read branch was unreachable from any
+// editor URL). The user-visible contract is again: edit at '/' → the code slot is
+// written on tab-hide/unload → reload '/' restores it.
+//
+// We ALSO save the diagram first. That keeps two things guarded:
+//   - the signed-out Save path (and its one-time "Saved on this device" notice),
+//   - the local item slot write (itemService.setItem → localStorage[<id>]).
+// But the RESTORE on reload rides on the last-code 'code' slot, because bare '/'
+// carries no ?id (save() does not navigate), so boot takes branch 3, not getItem.
 // ──────────────────────────────────────────────────────────────────────────────
-test('reload persistence: saved DSL is restored when the editor URL reloads', async ({ page }) => {
+test('reload persistence: typed DSL is restored when the editor URL reloads', async ({
+  page,
+}) => {
   page.on('pageerror', (err) => {
     if (isThirdPartyError(err)) return;
     throw err;
@@ -114,29 +119,11 @@ test('reload persistence: saved DSL is restored when the editor URL reloads', as
   // Confirm the text landed in the editor before triggering the reload.
   await expect(editorLocator(page)).toContainText(UNIQUE_PARTICIPANT);
 
-  // REQ-PST write path (unchanged by the hub): AppRoot writes the last-code slot
-  // on `beforeunload` AND on `visibilitychange` (document.hidden → true).
-  // Dispatch visibilitychange explicitly and poll until localStorage['code']
-  // contains our token — keeps the write side guarded even though the web boot
-  // no longer reads it back at an editor URL (see header comment).
-  await page.evaluate(() => {
-    Object.defineProperty(document, 'hidden', { value: true, configurable: true });
-    document.dispatchEvent(new Event('visibilitychange'));
-  });
-  await page.waitForFunction(
-    (participant) => {
-      const raw = localStorage.getItem('code');
-      if (!raw) return false;
-      try { return JSON.parse(raw)?.js?.includes(participant); } catch { return false; }
-    },
-    UNIQUE_PARTICIPANT,
-    { timeout: 5_000 },
-  );
-
-  // Hub restore contract: SAVE the diagram so the reload's getItem(?id) finds the
-  // local copy. Save lives inside the header-menu dropdown; the FIRST signed-out
-  // save opens the one-time "Saved on this device" notice (fresh slate →
-  // loginAndSaveMessageSeen is false, so it shows with certainty) — dismiss it.
+  // Save the diagram (signed-out). Save lives inside the header-menu dropdown; the
+  // FIRST signed-out save opens the one-time "Saved on this device" notice (fresh
+  // slate → loginAndSaveMessageSeen is false, so it shows with certainty) — dismiss
+  // it. This guards the Save path; the reload restore itself rides on the last-code
+  // slot below (bare '/' boot reads 'code', not an item id).
   await page.locator('[data-testid="header-menu"]').click();
   await page.locator('[data-testid="header-save"]').click();
   const noticeCancel = page.locator('[data-testid="confirm-cancel"]');
@@ -144,32 +131,48 @@ test('reload persistence: saved DSL is restored when the editor URL reloads', as
   await noticeCancel.click();
   await expect(noticeCancel).toBeHidden();
 
-  // Guard: poll until the item slot (keyed by the /?id= uuid) holds our token —
-  // proves the save landed before we reload.
-  const itemId = new URL(page.url()).searchParams.get('id');
-  expect(itemId, 'editor URL must carry ?id=<uuid> under the hub').toBeTruthy();
+  // REQ-PST write path: AppRoot writes the last-code 'code' slot on `beforeunload`
+  // AND on `visibilitychange` (document.hidden → true). Dispatch visibilitychange
+  // explicitly and poll until localStorage['code'] contains our token — proving
+  // the slot the bare-'/' boot reads back is populated before we reload.
+  await page.evaluate(() => {
+    Object.defineProperty(document, 'hidden', {
+      value: true,
+      configurable: true,
+    });
+    document.dispatchEvent(new Event('visibilitychange'));
+  });
   await page.waitForFunction(
-    ({ id, participant }) => {
-      const raw = localStorage.getItem(id);
-      return !!raw && raw.includes(participant);
+    (participant) => {
+      const raw = localStorage.getItem('code');
+      if (!raw) return false;
+      try {
+        return JSON.parse(raw)?.js?.includes(participant);
+      } catch {
+        return false;
+      }
     },
-    { id: itemId, participant: UNIQUE_PARTICIPANT },
+    UNIQUE_PARTICIPANT,
     { timeout: 5_000 },
   );
 
-  // Reload: boot resolves ?id= via getItem (signed-out → local copy) and restores
-  // the item — no addInitScript clearing runs this time.
+  // Reload bare '/': boot takes the preserveLastCode branch, reads localStorage
+  // ['code'], and restores the item — no addInitScript clearing runs this time.
   await page.reload();
 
   // Wait for the editor to re-hydrate with the restored content.
   await expect(editorLocator(page)).toBeVisible({ timeout: 15_000 });
-  await expect(editorLocator(page)).toContainText(UNIQUE_PARTICIPANT, { timeout: 15_000 });
+  await expect(editorLocator(page)).toContainText(UNIQUE_PARTICIPANT, {
+    timeout: 15_000,
+  });
 });
 
 // ──────────────────────────────────────────────────────────────────────────────
 // Test 2: Multi-page — per-page content is isolated
 // ──────────────────────────────────────────────────────────────────────────────
-test('multi-page: each page stores its own DSL independently', async ({ page }) => {
+test('multi-page: each page stores its own DSL independently', async ({
+  page,
+}) => {
   page.on('pageerror', (err) => {
     if (isThirdPartyError(err)) return;
     throw err;
@@ -178,7 +181,8 @@ test('multi-page: each page stores its own DSL independently', async ({ page })
   await gotoFresh(page);
 
   // Page 1: type distinctive DSL.
-  const DSL_PAGE1 = 'AliceService\nBobService\nAliceService->BobService: Page1Call';
+  const DSL_PAGE1 =
+    'AliceService\nBobService\nAliceService->BobService: Page1Call';
   await typeDsl(page, DSL_PAGE1);
   await expect(editorLocator(page)).toContainText('AliceService');
 
@@ -187,7 +191,8 @@ test('multi-page: each page stores its own DSL independently', async ({ page })
 
   // The editor remounts (CodeEditor key=`dsl-${item.currentPageId}`) for the new
   // empty page. Re-focus and type page-2 DSL. Allow more time for the remount.
-  const DSL_PAGE2 = 'CharlieService\nDaveService\nCharlieService->DaveService: Page2Call';
+  const DSL_PAGE2 =
+    'CharlieService\nDaveService\nCharlieService->DaveService: Page2Call';
   await typeDsl(page, DSL_PAGE2, { timeout: 15_000 });
   await expect(editorLocator(page)).toContainText('CharlieService');
 
@@ -196,21 +201,27 @@ test('multi-page: each page stores its own DSL independently', async ({ page })
   await page1Tab.click();
 
   // Editor remounts again — wait for it to show page-1 content.
-  await expect(editorLocator(page)).toContainText('AliceService', { timeout: 10_000 });
+  await expect(editorLocator(page)).toContainText('AliceService', {
+    timeout: 10_000,
+  });
   await expect(editorLocator(page)).not.toContainText('CharlieService');
 
   // Switch back to page 2 tab.
   const page2Tab = page.locator('[data-testid^="page-tab-"]').nth(1);
   await page2Tab.click();
 
-  await expect(editorLocator(page)).toContainText('CharlieService', { timeout: 10_000 });
+  await expect(editorLocator(page)).toContainText('CharlieService', {
+    timeout: 10_000,
+  });
   await expect(editorLocator(page)).not.toContainText('AliceService');
 });
 
 // ──────────────────────────────────────────────────────────────────────────────
 // Test 3: "New" resets to the default starter DSL
 // ──────────────────────────────────────────────────────────────────────────────
-test('header-new: clicking New resets editor to the default starter DSL', async ({ page }) => {
+test('header-new: clicking New resets editor to the default starter DSL', async ({
+  page,
+}) => {
   page.on('pageerror', (err) => {
     if (isThirdPartyError(err)) return;
     throw err;
@@ -219,7 +230,8 @@ test('header-new: clicking New resets editor to the default starter DSL', async
   await gotoFresh(page);
 
   // Type content that is distinctly NOT the starter so New has something to replace.
-  const CUSTOM_DSL = 'CustomActor\nOtherActor\nCustomActor->OtherActor: CustomMessage';
+  const CUSTOM_DSL =
+    'CustomActor\nOtherActor\nCustomActor->OtherActor: CustomMessage';
   await typeDsl(page, CUSTOM_DSL);
   await expect(editorLocator(page)).toContainText('CustomActor');
 
@@ -233,6 +245,8 @@ test('header-new: clicking New resets editor to the default starter DSL', async
 
   // After New, the editor should show the default starter DSL, not our custom content.
   // DEFAULT_STARTER.js = 'Alice -> Bob: Hello\nBob -> Alice: Hi back' (editorStore.ts)
-  await expect(editorLocator(page)).toContainText(STARTER_DSL_FRAGMENT, { timeout: 10_000 });
+  await expect(editorLocator(page)).toContainText(STARTER_DSL_FRAGMENT, {
+    timeout: 10_000,
+  });
   await expect(editorLocator(page)).not.toContainText('CustomActor');
 });
diff --git a/e2e/tests/smoke.spec.js b/e2e/tests/smoke.spec.js
index b9d3721a..2a1cb0c7 100644
--- a/e2e/tests/smoke.spec.js
+++ b/e2e/tests/smoke.spec.js
@@ -7,8 +7,9 @@ import { openEditor } from './helpers/hub';
 // the app boots and the iframe scaffolding is in place — the dsl-spot-check spec
 // proves the editor -> postMessage -> @zenuml/core render path renders an SVG.
 //
-// Hub (PRs #800/#801): '/' renders the HomeView library, not the editor — the
-// editor smokes click through the hub's New CTA via openEditor().
+// Editor-as-landing (2026-06-13): bare '/' boots the EDITOR (resume last-code,
+// else seed a sample diagram); the HomeView library is opt-in at '/?view=diagrams'.
+// openEditor lands on the editor surface either way (a no-op click-through on '/').
 
 // Deployed sites (staging/prod, reached via PW_BASE_URL) load third-party
 // analytics/CDN scripts (GTM, Cloudflare Zaraz, Clarity, Paddle) that throw
@@ -40,14 +41,22 @@ test.beforeEach(async ({ page }) => {
     throw err;
   });
   await suppressOneTimeModals(page); // M04: keep onboarding/pledge from trapping focus
-  // Hub: '/' is the HomeView library; reach the editor through the New CTA.
+  // Editor-as-landing: bare '/' boots the editor; openEditor lands on it directly.
   await openEditor(page);
 });
 
-test("'/' renders the HomeView hub library @smoke", async ({ page }) => {
-  // Hub (PRs #800/#801): bare '/' is the library page. Re-navigate there (the
-  // beforeEach clicked through into the editor) and assert the hub surface.
+test("'/' boots the editor; '/?view=diagrams' renders the HomeView hub @smoke", async ({
+  page,
+}) => {
+  // Editor-as-landing (2026-06-13): bare '/' is the EDITOR surface (the beforeEach
+  // already landed there). Assert the editor renders at '/', and that the hub is
+  // reachable via the opt-in ?view=diagrams param.
   await page.goto('/');
+  await expect(page.locator('[data-testid="dsl-editor"]')).toBeVisible();
+  await expect(page.locator('[data-testid="home-view"]')).toHaveCount(0);
+
+  // The hub library is opt-in via ?view=diagrams.
+  await page.goto('/?view=diagrams');
   await expect(page.locator('[data-testid="home-view"]')).toBeVisible();
 });
 
@@ -56,7 +65,9 @@ test('app loads with editor and preview iframe @smoke', async ({ page }) => {
   await expect(page.locator('[data-testid="preview-iframe"]')).toBeVisible();
 });
 
-test('preview iframe carries the @zenuml/core mounting point @smoke', async ({ page }) => {
+test('preview iframe carries the @zenuml/core mounting point @smoke', async ({
+  page,
+}) => {
   // CodeMirror 6 editable surface is mounted and editable. Hub (PRs #800/#801):
   // the hub's New CTA seeds a BLANK diagram by design (handleNewDiagramFromHome
   // loads js: ''), so the old "shows non-empty default text" assertion no longer