[Bug] Welcome screen shown again after navigation — existing wallet session not auto-loaded

## Description
After creating a wallet and navigating away, returning to the root URL shows the onboarding screen instead of the dashboard.

## Steps to Reproduce
1. Create a wallet
2. Navigate to /terms-of-service
3. Navigate back to /

## Expected Behavior
App detects existing wallet and loads dashboard directly.

## Actual Behavior
Welcome/onboarding screen shown again.

## Severity
Medium