fix(editor): restore click-to-focus on editor padding area

[j4rviscmd]

Summary

Restore the handleWrapperClick callback that was accidentally removed in commit 3e11cb6 (checklist split fix). This re-enables the behaviour where clicking in the pb-[60vh] padding zone below the editor content focuses the editor at the end of the last block.

Also adds a locked mode guard so the handler is a no-op when the note is in read-only mode.

Related Issue

N/A — Regression fix (feature was added in 9c3ea37, removed in 3e11cb6)

Type of Change

• ✨ New feature
• 💥 Breaking change
• 🐛 Bug fix
• 📝 Documentation
• ♻️ Refactoring
• 🔧 Chore

Breaking Changes

None

Test

• Run npm run dev
• Open a note with content
• Click in the empty area below the note content (the padding area)
• Verify the cursor moves to the end of the last block and the editor gains focus
• Lock a note and verify clicking the padding area does nothing

Checklist

• Code follows clean architecture (proper separation of concerns)
• Code is simple and concise (no unnecessary complexity)
• Comments are sufficient for non-obvious logic
• No sensitive information included (credentials, secrets, personal data)
• Conventional Commits format followed in commit messages
• Tests added/updated (or N/A for docs/chore)