style: Apply cargo fmt and clippy fixes across codebase

Automated formatting and lint corrections from parallel agent work:

- cargo fmt: import reordering (alphabetical), line wrapping to respect
  max width, trailing comma normalization, destructuring alignment,
  function signature reformatting, match arm formatting
- clippy (pedantic): Range::contains() instead of manual comparisons,
  i64::from() instead of `as i64` casts, .clamp() instead of
  .max().min() chains, let-chain refactors (if-let with &&),
  #[allow(clippy::too_many_arguments)] and
  #[allow(clippy::field_reassign_with_default)] where warranted
- Removed trailing blank lines and extra whitespace

No behavioral changes. All existing tests pass unmodified.

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

src/gitlab/transformers/discussion.rs

@@ -179,10 +179,7 @@ fn transform_single_note(
         resolvable: note.resolvable,
         resolved: note.resolved,
         resolved_by: note.resolved_by.as_ref().map(|a| a.username.clone()),
-        resolved_at: note
-            .resolved_at
-            .as_ref()
-            .and_then(|ts| iso_to_ms(ts)),
+        resolved_at: note.resolved_at.as_ref().and_then(|ts| iso_to_ms(ts)),
         position_old_path,
         position_new_path,
         position_old_line,
@@ -235,7 +232,6 @@ fn extract_position_fields(
     }
 }
 
-
 /// Transform notes from a GitLab discussion with strict timestamp parsing.
 /// Returns Err if any timestamp is invalid - no silent fallback to 0.
 pub fn transform_notes_with_diff_position(