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/search/vector.rs

@@ -70,7 +70,7 @@ pub fn search_vector(
          FROM embeddings
          WHERE embedding MATCH ?1
            AND k = ?2
-         ORDER BY distance"
+         ORDER BY distance",
     )?;
 
     let rows: Vec<(i64, f64)> = stmt
@@ -137,11 +137,7 @@ mod tests {
 
     #[test]
     fn test_dedup_respects_limit() {
-        let rows = vec![
-            (1000_i64, 0.1_f64),
-            (2000, 0.2),
-            (3000, 0.3),
-        ];
+        let rows = vec![(1000_i64, 0.1_f64), (2000, 0.2), (3000, 0.3)];
         let results = search_vector_dedup(rows, 2);
         assert_eq!(results.len(), 2);
     }
@@ -161,7 +157,10 @@ mod tests {
         }
         let mut results: Vec<VectorResult> = best
             .into_iter()
-            .map(|(document_id, distance)| VectorResult { document_id, distance })
+            .map(|(document_id, distance)| VectorResult {
+                document_id,
+                distance,
+            })
             .collect();
         results.sort_by(|a, b| a.distance.total_cmp(&b.distance));
         results.truncate(limit);