This PR implements spelling correction feature requested in issue #271 
    
<!-- This is an auto-generated description by cubic. -->
---

## Summary by cubic
Add spell check suggestions to the context menu in editable fields.
Right-clicking a misspelled word shows up to five suggestions for
one-click replacement.

- **New Features**
- Shows a “Correct "<misspelled>"” submenu when a misspelled word is
detected.
- Provides up to 5 dictionary suggestions; clicking replaces the word
via replaceMisspelling.
- Keeps standard edit actions and tidies menu order with separators;
logs errors on failure.

<!-- End of auto-generated description by cubic. -->