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/ingestion/merge_requests.rs

@@ -17,10 +17,10 @@ use crate::core::error::{LoreError, Result};
 use crate::core::payloads::{StorePayloadOptions, store_payload};
 use crate::core::time::now_ms;
 use crate::documents::SourceType;
-use crate::ingestion::dirty_tracker;
 use crate::gitlab::GitLabClient;
 use crate::gitlab::transformers::merge_request::transform_merge_request;
 use crate::gitlab::types::GitLabMergeRequest;
+use crate::ingestion::dirty_tracker;
 
 /// Result of merge request ingestion.
 #[derive(Debug, Default)]