add bracketed paste support for TUI inputs

[evanbranigan-dotcom]

Summary

• Enable crossterm's bracketed paste mode on startup so pasted text arrives as a single Event::Paste(String) instead of individual key events
• Handle Event::Paste in all three input components (MnemonicInput, PathInput, BirthdayInput)
• Strip surrounding quotes from pasted paths (macOS adds quotes on file drag-and-drop)
• Disable bracketed paste on both normal exit and panic hook

Problem

Without bracketed paste mode, the terminal sends pasted text character-by-character. This causes:

• macOS: Dragging a file wraps the path in single quotes ('path')
• Linux/KDE: A spurious j character is prepended (partial parse of the ESC[200~ sequence)
• All platforms: Pasting a 24-word mnemonic triggers 100+ individual key events instead of one paste event

Changes

File	Change
main.rs	EnableBracketedPaste on startup, DisableBracketedPaste on exit + panic
mnemonic_input.rs	Handle Event::Paste — type each character
input.rs (PathInput)	Handle Event::Paste — strip quotes, type each character
birthday_input.rs	Handle Event::Paste — type each character

No dependency changes — crossterm 0.29.0 (already in the lock file) has full support, and tuirealm 2.2.0 already surfaces Event::Paste(String).

Fixes #43

AI Disclosure

Claude (Anthropic) assisted with codebase analysis and patch authoring. All code was reviewed and understood by the committer.