Find & Replace dialog (Ctrl/Cmd+F, Ctrl/Cmd+H)

[Mandip77]

Summary

Provide a small dialog for Find & Replace (case-sensitive toggle).

Tasks

• Add menu items + accelerators.
• Build a modal dialog with fields: "Find", "Replace", checkboxes: "Match case", "Replace All".
• Implement "Find Next", "Replace", "Replace All".
• Highlight current match (optional).

Acceptance Criteria

• User can search forward and replace matches.
• Replace All operates on full text safely.

Hints

• Use TextInputDialog/custom Dialog.
• For search: use regex or indexOf depending on "Match case".