Add --wrap-word-lookback for word-aware line wrapping

src/cli.rs

@@ -920,6 +920,14 @@ pub struct Opt {
     /// --max-line-distance=1.0 (this is more similar to `git --word-diff`).
     pub tokenization_regex: String,
 
+    #[arg(long = "wrap-word-lookback", default_value = "0", value_name = "N")]
+    /// Prefer a word-friendly wrap point within the last N columns before the column boundary.
+    ///
+    /// Within that window delta prefers whitespace, otherwise the nearest non-word character.
+    /// 0 (default) wraps exactly at the column boundary.
+    /// Has no effect unless delta is wrapping long lines (e.g. in side-by-side mode).
+    pub wrap_word_lookback: usize,
+
     #[arg(long = "wrap-left-symbol", default_value = "↵", value_name = "STRING")]
     /// End-of-line wrapped content symbol (left-aligned).
     ///

src/features/side_by_side.rs

@@ -156,6 +156,7 @@ pub fn paint_minus_and_plus_lines_side_by_side(
         // Calculated for syntect::highlighting::style::Style and delta::Style
         wrap_minusplus_block(
             config,
+            lines,
             syntax_sections,
             diff_sections,
             &line_alignment,

src/options/set.rs

@@ -214,6 +214,7 @@ pub fn set_options(
             show_colors,
             show_themes,
             side_by_side,
+            wrap_word_lookback,
             wrap_max_lines,
             wrap_right_prefix_symbol,
             wrap_right_percent,