🤖 fix: one main landmark in immersive review and on pages without a workspace

[ThomasK33]

Summary

#5967 gave the workspace page one main landmark, inside the chat pane. Immersive review hides the chat pane, and the pages with no workspace have no chat pane at all, so those layouts had no main landmark. This PR makes the primary view of each of those layouts its main. Every one now has exactly one, and the pages look the same as before.

Fixes #5969

Changes

Each production file changes only its root element from <div> to <main> and adds one comment. Classes and props are unchanged.

Layout	Owner of main	File
Immersive review	ImmersiveReviewView root (portaled into #review-immersive-root)	ImmersiveReviewView.tsx
No project or workspace (/)	RootRouteShell	App.tsx
Project creation page	ProjectPage root	ProjectPage.tsx
Scratch chat creation page	ScratchPage root	ScratchPage.tsx

• While immersive review is open, the chat pane root is hidden, inert and aria-hidden, so its main leaves the accessibility tree. The immersive view is then the page's only main.
• ImmersiveReviewView's containerRef widens from HTMLDivElement to HTMLElement. It is only used for focus() and querySelector.
• WorkspaceShell.tsx is not touched.

Validation

• Test first: 8 new stories in App.seededWorkspaceA11y.stories.tsx cover immersive review and the root, project and scratch pages, each at desktop width and at 390 px (fixed-width wrapper plus globals.viewport, Pixel disabled). Each play asserts exactly one role="main" that contains the layout's content, and contains neither navigation "Projects", nor complementary "Workspace insights", nor contentinfo. On main, all 8 fail with "Unable to find role="main"".
• Reverting any one of the 4 production files breaks exactly that layout's 2 stories and nothing else.
• Chromium's accessibility tree: each layout gains exactly one main, and its other landmarks are unchanged.
• All 8 layouts are pixel-identical to main.
• Lighthouse 13.5.0 confirms no regression on first-run and the seeded page (Accessibility 100, landmark-one-main passes), but its setup cannot reach the pages this PR fixes, so the stories above are the evidence for the fix.
• make check-react-compiler reports 23/24 (the 1 known skip is ProjectSidebarInner). ImmersiveReviewView still compiles.
• The full Storybook suite passes (657 passed, 1 skipped). One earlier full run had a single failure in App/MemoryIntuition (a story these files do not render). That story then passed 3 of 3 runs on its own on this branch and 3 of 3 with main's versions of the 4 files, and two full reruns passed.

Notes

• The notes sidebar stays inside main in desktop immersive review. Its <aside> (complementary) was a top-level landmark and now sits inside the immersive view's main. ARIA allows a complementary landmark inside main. axe's best-practice rule landmark-complementary-is-top-level flags it.
• Loading states are out of scope. "Opening workspace..." (App.tsx), and the "Loading workspace..." and "No Workspace Selected" placeholders (WorkspaceShell.tsx) still have no main landmark. 🤖 a11y: main landmark missing in loading and placeholder states #5998 tracks them, after the perf work that edits WorkspaceShell.tsx lands.

Screenshots

These show this branch. They are pixel-identical to main.

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[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-10T01:30:05.133779Z	7c8865d	PR opened
🔒 Security Review	✅ Completed 2026-10-10T01:30:36.850192Z	7c8865d	PR opened

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