Feature: Landing page on root route

[mjkatgithub]

Goal

Turn / into a dedicated landing page with product messaging and explicit
login entry.

Scope

• Replace mount-time auto-redirect behavior on /
• Add landing hero/content blocks and app-bar login button
• Add native app download CTA placeholder for future phase
• Keep login flow reachable from landing without implicit redirects

Branch

feature/root-landing-page

Acceptance Criteria

• Visiting / shows landing content instead of immediate navigation
• Landing includes clear login CTA in app bar
• Download CTA is present as placeholder-only (no full flow yet)
• Routing remains stable for authenticated and unauthenticated users

Test Checklist

Unit

• Landing rendering conditions and CTA actions

Integration

• Root route no longer performs immediate redirect on mount
• Login CTA navigates reliably to login flow

E2E

• Open / logged out and verify landing content appears
• Use login CTA and verify navigation to auth page