fix(clippy): resolve field_reassign_with_default and needless_range_loop warnings

Author: unhappychoice

src/game/screens/typing_screen.rs

@@ -68,8 +68,10 @@ impl TypingScreen {
         challenge: &Challenge,
         repo_info: Option<GitRepository>,
     ) -> Result<Self> {
-        let mut options = ProcessingOptions::default();
-        options.preserve_empty_lines = true; // Always preserve empty lines for challenges
+        let options = ProcessingOptions {
+            preserve_empty_lines: true, // Always preserve empty lines for challenges
+            ..Default::default()
+        };
 
         let typing_core =
             TypingCore::new(&challenge.code_content, &challenge.comment_ranges, options);

src/game/typing_core.rs

@@ -371,11 +371,11 @@ impl TypingCore {
         }
 
         // Check if rest of line contains only whitespace
-        for i in type_pos..chars.len() {
-            if chars[i] == '\n' {
+        for &ch in chars.iter().skip(type_pos) {
+            if ch == '\n' {
                 return true;
             }
-            if !chars[i].is_whitespace() {
+            if !ch.is_whitespace() {
                 return false;
             }
         }