fix(ui): Fix hardware tier display mappings

- Update NavbarAuth to show OS-based tiers instead of robotics tiers
- tier1: Windows PC (was Laptop/Cloud)
- tier2: Mac (was RTX GPU)
- tier3: Linux (was Jetson Edge)
- tier4: Chromebook/Web (was Physical Robot)
- Aligns with auth-server signup/profile form tier system

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: mjunaidca

robolearn-interface/src/components/NavbarAuth/index.tsx

@@ -144,6 +144,8 @@ export function NavbarAuth() {
                   )}
                   {session.user.hardwareTier && (
                     <div className={styles.profileItem}>
+                      <span className={styles.profileLabel}>Hardware:</span>
+                      <span className={styles.profileValue}>
                         {session.user.hardwareTier === 'tier1' ? 'Windows PC' :
                          session.user.hardwareTier === 'tier2' ? 'Mac' :
                          session.user.hardwareTier === 'tier3' ? 'Linux' :