test: Remove redundant comments from test files

Applies the same doc comment cleanup to test files:
- Removes test module headers (//! lines)
- Removes obvious test function comments
- Retains comments explaining non-obvious test scenarios

Test names should be descriptive enough to convey intent without
additional comments. Complex test setup or assertions that need
explanation retain their comments.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/diffnote_position_tests.rs

@@ -1,5 +1,3 @@
-//! Tests for DiffNote position extraction in note transformer.
-
 use lore::gitlab::transformers::discussion::transform_notes_with_diff_position;
 use lore::gitlab::types::{
     GitLabAuthor, GitLabDiscussion, GitLabLineRange, GitLabLineRangePoint, GitLabNote,
@@ -60,8 +58,6 @@ fn make_discussion(notes: Vec<GitLabNote>) -> GitLabDiscussion {
     }
 }
 
-// === DiffNote Position Field Extraction ===
-
 #[test]
 fn extracts_position_paths_from_diffnote() {
     let position = GitLabNotePosition {
@@ -174,7 +170,7 @@ fn line_range_uses_old_line_fallback_when_new_line_missing() {
             line_code: None,
             line_type: Some("old".to_string()),
             old_line: Some(20),
-            new_line: None, // missing - should fall back to old_line
+            new_line: None,
         },
         end: GitLabLineRangePoint {
             line_code: None,
@@ -203,8 +199,6 @@ fn line_range_uses_old_line_fallback_when_new_line_missing() {
     assert_eq!(notes[0].position_line_range_end, Some(25));
 }
 
-// === Regular Notes (non-DiffNote) ===
-
 #[test]
 fn regular_note_has_none_for_all_position_fields() {
     let note = make_basic_note(1, "2024-01-16T09:00:00.000Z");
@@ -224,8 +218,6 @@ fn regular_note_has_none_for_all_position_fields() {
     assert_eq!(notes[0].position_head_sha, None);
 }
 
-// === Strict Timestamp Parsing ===
-
 #[test]
 fn returns_error_for_invalid_created_at_timestamp() {
     let mut note = make_basic_note(1, "2024-01-16T09:00:00.000Z");
@@ -264,8 +256,6 @@ fn returns_error_for_invalid_resolved_at_timestamp() {
     assert!(result.is_err());
 }
 
-// === Mixed Discussion (DiffNote + Regular Notes) ===
-
 #[test]
 fn handles_mixed_diffnote_and_regular_notes() {
     let position = GitLabNotePosition {
@@ -286,16 +276,12 @@ fn handles_mixed_diffnote_and_regular_notes() {
     let notes = transform_notes_with_diff_position(&discussion, 100).unwrap();
 
     assert_eq!(notes.len(), 2);
-    // First note is DiffNote with position
     assert_eq!(notes[0].position_new_path, Some("file.rs".to_string()));
     assert_eq!(notes[0].position_new_line, Some(42));
-    // Second note is regular with None position fields
     assert_eq!(notes[1].position_new_path, None);
     assert_eq!(notes[1].position_new_line, None);
 }
 
-// === Position Preservation ===
-
 #[test]
 fn preserves_note_position_index() {
     let pos1 = GitLabNotePosition {
@@ -330,11 +316,8 @@ fn preserves_note_position_index() {
     assert_eq!(notes[1].position, 1);
 }
 
-// === Edge Cases ===
-
 #[test]
 fn handles_diffnote_with_empty_position_fields() {
-    // DiffNote exists but all position fields are None
     let position = GitLabNotePosition {
         old_path: None,
         new_path: None,
@@ -351,7 +334,6 @@ fn handles_diffnote_with_empty_position_fields() {
 
     let notes = transform_notes_with_diff_position(&discussion, 100).unwrap();
 
-    // All position fields should be None, not cause an error
     assert_eq!(notes[0].position_old_path, None);
     assert_eq!(notes[0].position_new_path, None);
 }
@@ -376,6 +358,5 @@ fn handles_file_position_type() {
 
     assert_eq!(notes[0].position_type, Some("file".to_string()));
     assert_eq!(notes[0].position_new_path, Some("binary.bin".to_string()));
-    // File-level comments have no line numbers
     assert_eq!(notes[0].position_new_line, None);
 }