chore: bump version to 2026.5.4

[richardthe3rd]

Summary

• Bumps `pubspec.yaml` version from `2026.5.3+20260510` to `2026.5.4+20260511`

Release steps after merge

1. Merge this PR
2. Tag the merge commit: `git tag v2026.5.4 && git push origin v2026.5.4`
3. This triggers `release-web.yml` and `release-android.yml` automatically

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Bumps the Flutter app’s package/build version in pubspec.yaml to prepare the next release tag (v2026.5.4) and associated web/Android release workflows.

Changes:

• Update pubspec.yaml version from 2026.5.3+20260510 to 2026.5.4+20260511.

[github-actions]

LCOV of commit c87df8d during CI #148

Summary coverage rate:
  lines......: 77.0% (2420 of 3142 lines)
  functions..: no data found
  branches...: no data found

Files changed coverage rate: n/a

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!

[github-actions]

🚀 Cloudflare Pages Preview

Your preview deployment is ready!

Preview URL: https://worktree-release-2026-5-4.staging-cambeerfestival.pages.dev

This preview will be automatically updated when you push new commits to this PR.