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/mr_transformer_tests.rs

@@ -1,5 +1,3 @@
-//! Tests for MR transformer module.
-
 use lore::gitlab::transformers::merge_request::transform_merge_request;
 use lore::gitlab::types::{GitLabAuthor, GitLabMergeRequest, GitLabReferences, GitLabReviewer};
 
@@ -63,7 +61,7 @@ fn transforms_mr_with_all_fields() {
 
     assert_eq!(result.merge_request.gitlab_id, 12345);
     assert_eq!(result.merge_request.iid, 42);
-    assert_eq!(result.merge_request.project_id, 200); // Local project ID, not GitLab's
+    assert_eq!(result.merge_request.project_id, 200);
     assert_eq!(result.merge_request.title, "Add user authentication");
     assert_eq!(
         result.merge_request.description,
@@ -105,22 +103,17 @@ fn parses_timestamps_to_ms_epoch() {
     let mr = make_test_mr();
     let result = transform_merge_request(&mr, 200).unwrap();
 
-    // 2024-01-15T10:00:00.000Z = 1705312800000 ms
     assert_eq!(result.merge_request.created_at, 1705312800000);
-    // 2024-01-20T14:30:00.000Z = 1705761000000 ms
     assert_eq!(result.merge_request.updated_at, 1705761000000);
-    // merged_at should also be parsed
     assert_eq!(result.merge_request.merged_at, Some(1705761000000));
 }
 
 #[test]
 fn handles_timezone_offset_timestamps() {
     let mut mr = make_test_mr();
-    // GitLab can return timestamps with timezone offset
     mr.created_at = "2024-01-15T05:00:00-05:00".to_string();
 
     let result = transform_merge_request(&mr, 200).unwrap();
-    // 05:00 EST = 10:00 UTC = same as original test
     assert_eq!(result.merge_request.created_at, 1705312800000);
 }
 
@@ -322,7 +315,6 @@ fn handles_closed_at_timestamp() {
 
     let result = transform_merge_request(&mr, 200).unwrap();
     assert!(result.merge_request.merged_at.is_none());
-    // 2024-01-18T12:00:00.000Z = 1705579200000 ms
     assert_eq!(result.merge_request.closed_at, Some(1705579200000));
 }