fix: address PR review feedback — Rust lifetimes and shebang detection

- Skip single-quote tracking for Rust in find_function_end (lifetimes
  like 'a/'static are not string delimiters, were breaking brace count)
- Add #!/ to HASH_NON_COMMENT_PREFIXES so shebang lines are not
  misclassified as comments (changing interpreter is a real code change)
- Added 2 regression tests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: haasonsaas

src/core/function_chunker.rs

@@ -265,7 +265,7 @@ fn find_function_end(lines: &[&str], start: usize, language: &str) -> usize {
                         escaped = true;
                     } else if ch == '"' && !in_single_quote {
                         in_double_quote = !in_double_quote;
-                    } else if ch == '\'' && !in_double_quote {
+                    } else if ch == '\'' && !in_double_quote && language != "rs" {
                         in_single_quote = !in_single_quote;
                     } else if !in_double_quote && !in_single_quote {
                         if ch == '{' {
@@ -934,6 +934,24 @@ fn next_func() {
         );
     }
 
+    #[test]
+    fn test_find_function_end_rust_lifetime_not_string() {
+        // BUG: Rust lifetime annotations ('a, 'static) toggle in_single_quote,
+        // causing the opening brace on the same line to be ignored.
+        let lines: Vec<&str> = vec![
+            "pub fn new(name: &'static str) -> Self {", // line 0: has lifetime '
+            "    Self { name }",                        // line 1
+            "}",                                        // line 2
+            "",
+            "fn other() {",                             // line 4
+        ];
+        let end = find_function_end(&lines, 0, "rs");
+        assert_eq!(
+            end, 2,
+            "Rust lifetime annotation should not break brace tracking"
+        );
+    }
+
     #[test]
     fn test_find_function_end_escaped_backslash_in_string() {
         // A string containing "\\" (escaped backslash) on the same line as braces.

src/review/triage.rs

@@ -45,8 +45,8 @@ const COMMENT_PREFIXES: &[&str] = &["//", "# ", "/*", "*/", "* ", "--", "<!--",
 
 /// Patterns that start with `#` but are NOT comments (Rust attributes, C preprocessor, etc.).
 const HASH_NON_COMMENT_PREFIXES: &[&str] = &[
-    "#[", "#![", "#include", "#define", "#ifdef", "#ifndef", "#endif", "#pragma", "#undef", "#elif",
-    "#else", "#if ", "#error", "#warning", "#line",
+    "#[", "#![", "#!/", "#include", "#define", "#ifdef", "#ifndef", "#endif", "#pragma", "#undef",
+    "#elif", "#else", "#if ", "#error", "#warning", "#line",
 ];
 
 /// Classify a diff using fast heuristics (no LLM call).
@@ -983,6 +983,20 @@ mod tests {
         assert_eq!(triage_diff(&diff), TriageResult::SkipCommentOnly);
     }
 
+    #[test]
+    fn test_shebang_line_is_not_comment() {
+        // Shebang lines (#!/usr/bin/env python3) change runtime behavior
+        // and should NOT be classified as comments
+        let diff = make_diff(
+            "script.py",
+            vec![
+                make_line(1, ChangeType::Removed, "#!/usr/bin/env python2"),
+                make_line(1, ChangeType::Added, "#!/usr/bin/env python3"),
+            ],
+        );
+        assert_eq!(triage_diff(&diff), TriageResult::NeedsReview);
+    }
+
     #[test]
     fn test_all_blank_lines_is_comment_only() {
         // Blank lines count as "comment" in is_comment_line