feat(ui): desktop page navigation + New Chat fix

[dimakis]

Summary

• Adds DesktopNav component to the left sidebar so desktop users can navigate to Calendar, Inbox, Telos, Tasks, and Files (previously only reachable by typing URLs)
• Non-chat pages now render inside DesktopShell on desktop via PageRoute wrapper — nav sidebar on the left, no right panel
• Fixes the New Chat button which was broken because history.replaceState desynchronized React Router — handleNewChat now calls storeNewSession() directly

Test plan

• DesktopShell tests updated and passing (7/7)
• TypeScript clean (no frontend errors)
• Manual: verify nav items render in left sidebar on desktop
• Manual: verify clicking nav items navigates to correct pages
• Manual: verify active state highlighting
• Manual: verify New Chat button creates fresh session
• Manual: verify mobile layout unchanged (TabBar still works)

🤖 Generated with Claude Code

[dimakis]

Centaur Review

Found 4 issue(s) (3 warning).

frontend/src/components/DesktopNav.tsx

Solid feature PR — the New Chat fix is correct (storeNewSession clears store state before navigation), and DesktopShell's optional props cleanly support the new PageRoute pattern. Main gap is missing tests for the new DesktopNav component and the center-only DesktopShell rendering path.

• 🟡 missing_tests: New component has no unit tests. It contains routing logic (match functions), badge rendering, and navigation — all worth covering. The project follows TDD, so tests should exist alongside the implementation. [fixable]
• 🔵 style (L16): The items array (with its closures) is re-allocated on every render. For 6 items this is negligible, but wrapping it in useMemo(() => [...], [inboxCount, todoCount]) would make dependencies explicit and avoid the allocation when only location changes. [fixable]

frontend/src/components/__tests__/DesktopShell.test.tsx

Solid feature PR — the New Chat fix is correct (storeNewSession clears store state before navigation), and DesktopShell's optional props cleanly support the new PageRoute pattern. Main gap is missing tests for the new DesktopNav component and the center-only DesktopShell rendering path.

• 🟡 missing_tests: No test covers the new center-only rendering path (right omitted). The PR made right optional and wrapped it in a conditional ({right && ...}), but every existing test still passes right. A test rendering <DesktopShell center={...} /> without left/right would verify the PageRoute usage path and confirm the right sidebar collapse button is correctly absent. [fixable]

frontend/src/components/DesktopShell.tsx

Solid feature PR — the New Chat fix is correct (storeNewSession clears store state before navigation), and DesktopShell's optional props cleanly support the new PageRoute pattern. Main gap is missing tests for the new DesktopNav component and the center-only DesktopShell rendering path.

• 🟡 bugs (L63): When left is undefined (the PageRoute case), the left sidebar still renders DesktopNav and the collapse toggle — which is the desired behavior. However, when the sidebar is collapsed and then expanded, the fragment renders <DesktopNav /> followed by {undefined}. This is harmless in React (undefined children are ignored), but worth noting: there's no visual separator or empty-state handling between the nav and a missing session panel. If the left sidebar should be entirely hidden when no left content exists, wrap the whole sidebar in a conditional too.

[dimakis]

🔵 style: The items array (with its closures) is re-allocated on every render. For 6 items this is negligible, but wrapping it in useMemo(() => [...], [inboxCount, todoCount]) would make dependencies explicit and avoid the allocation when only location changes. [fixable]

[dimakis]

🟡 bugs: When left is undefined (the PageRoute case), the left sidebar still renders DesktopNav and the collapse toggle — which is the desired behavior. However, when the sidebar is collapsed and then expanded, the fragment renders <DesktopNav /> followed by {undefined}. This is harmless in React (undefined children are ignored), but worth noting: there's no visual separator or empty-state handling between the nav and a missing session panel. If the left sidebar should be entirely hidden when no left content exists, wrap the whole sidebar in a conditional too.