Windows accessibility: sidebar Graph and Quick Chats destinations don't expose UIA selection state #801

Describe the bug
The Windows sidebar's static navigation destinations, the pinned Graph overview and Quick Chats, don't expose their selected state through native UI Automation:

• graphcode-windows/src/AccessibilityProvider.cpp, about lines 853-865, keeps only the bounds of the static overview and Quick Chats elements and discards their selected flags;
• supportsSelectionItem/get_IsSelected admit only dynamic row keys (project and loop rows).

So the app-side unit sink sees Graph selected, but a screen reader or the UIA client cannot. On macOS these are selectable List rows (AppSidebarView.swift:300-310, .chats, .project, .node).

Expected behavior

• Each sidebar navigation destination (Graph, Quick Chats, project, loop) exposes SelectionItem, with IsSelected matching the painted selection.
• The container's GetSelection returns exactly the one selected destination.
• Select routes through the existing Invoke action.

Additional context
Found 2026-10-14 by lane C (#767, PR #800) while adding an "exactly one selected navigation row" UIA oracle. #800 keeps that oracle to the navigation rows the native provider exposes today, and defers the native Graph/Quick Chats selection proof to this issue.

Related: the sidebar's Needs-you rows reuse selected_node_id (App.zig, about line 7777), so they report a second selected alias. macOS has no sidebar Needs-you section: AppSidebarView.swift:334 has attentionSection commented out. #767 already tracks removing it as a Windows extra.

Current implementation

• PR #968 implements and qualifies the native sidebar selection contract. Keep this issue open until the PR merges and the issue is re-audited against the ledger.