Fix remaining Dependabot security alerts (#2804)

## Summary
- **Rails example**: Upgrade Rails 7.1.6 → 7.2.3.1 to fix 8 alerts:
activestorage path traversal/glob injection/DoS/content type bypass,
activesupport ReDoS/DoS/XSS, and actionview XSS
- **Django example**: Update sqlparse 0.5.3 → 0.5.4 (DoS via formatting
list of tuples)
- **Drupal example**: Update psysh v0.12.15 → v0.12.19 (local privilege
escalation via CWD .psysh.php auto-load)

## Test plan
- [x] Verify `go build ./...` still passes (no Go changes)
- [ ] Confirm Dependabot alerts are resolved after merge

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

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>