Update PR placeholder with actual PR number in TURBO_NAVIGATION_TEST_ISSUE.md

Replaced "PR #XXXX" with "PR #1896" since commit f03b935 that fixed
the Turbo navigation bug is part of this PR.

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

Co-Authored-By: Claude <noreply@anthropic.com>

Author: justin808

TURBO_NAVIGATION_TEST_ISSUE.md

@@ -15,7 +15,7 @@ A regression was discovered where JavaScript fails to work after navigating betw
 - Set `turbo: true` in ReactOnRails options
 - **Forgot to update layout file** from `data-turbolinks-track` to `data-turbo-track`
 
-**Bug fixed in:** PR #XXXX (commit f03b935d)
+**Bug fixed in:** PR #1896 (commit f03b935d)
 
 - Updated `spec/dummy/app/views/layouts/application.html.erb`
 - Changed `data-turbolinks-track: true` to `data-turbo-track: 'reload'`