Refactor: simplify word navigation logic, improve line wrapping, and enhance parameter initialization across core and TUI modules.

crates/owlen-core/src/ui.rs

@@ -305,9 +305,7 @@ pub fn find_word_end(line: &str, col: usize) -> Option<usize> {
             pos += 1;
         }
         // Move back one to be ON the last character
-        if pos > 0 {
-            pos -= 1;
-        }
+        pos = pos.saturating_sub(1);
     } else {
         // Skip non-word characters
         while pos < chars.len() && !is_word_char(chars[pos]) {
@@ -317,9 +315,7 @@ pub fn find_word_end(line: &str, col: usize) -> Option<usize> {
         while pos < chars.len() && is_word_char(chars[pos]) {
             pos += 1;
         }
-        if pos > 0 {
-            pos -= 1;
-        }
+        pos = pos.saturating_sub(1);
     }
 
     Some(pos)
@@ -336,9 +332,7 @@ pub fn find_prev_word_boundary(line: &str, col: usize) -> Option<usize> {
     let is_word_char = |c: char| c.is_alphanumeric() || c == '_';
 
     // Move back one position first
-    if pos > 0 {
-        pos -= 1;
-    }
+    pos = pos.saturating_sub(1);
 
     // Skip non-word characters
     while pos > 0 && !is_word_char(chars[pos]) {