feat: (cosmetic) nicer word wrap

[N4M3Z]

Wrap mode pre-expands long lines manually instead of delegating to Ratatui's Wrap. Continuation rows preserve the gutter structure so line numbers and diff markers stay aligned.

  42 ▌ let very_long_variable_name = some_func
   ↪ ▌ tion_call(argument_one, argument_two,
   ↪ ▌ argument_three);

• Continuation rows show ↪ in the line-number column and preserve the diff origin marker (▌) so add/del coloring stays consistent across wrapped visual rows.
• Overlay painting (cursor highlight, visual selection, diff backgrounds) uses content-adjusted widths (viewport minus gutter) for row prediction, matching the pre-expansion break points exactly.
• :wrap toggles wrap on/off (alias for the existing :set wrap!).

Test plan

• cargo fmt && cargo clippy -- -D warnings clean
• cargo test --lib passes (839 tests)
• Manual: :wrap on a file with long lines shows ↪ ▌ on continuation rows, content aligned with original line
• Manual: cursor-line highlight spans all visual rows of a wrapped line
• Manual: visual selection (V) highlight tracks the cursor correctly on wrapped lines
• Manual: toggling :wrap off restores horizontal scroll mode with no visual artifacts

[N4M3Z]

That should be it from my side for now to use this as a daily driver, I might send some minor stuff but now I gotta actually start working ) Thanks for the quick responses on my PRs

[N4M3Z]

I just noticed the wrap is breaking words affecting readability, will submit a fix

[N4M3Z]

#385