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>

tests/migration_tests.rs

@@ -26,7 +26,7 @@ fn apply_migrations(conn: &Connection, through_version: i32) {
 
         let sql = std::fs::read_to_string(entries[0].path()).unwrap();
         conn.execute_batch(&sql)
-            .expect(&format!("Migration {} failed", version));
+            .unwrap_or_else(|e| panic!("Migration {} failed: {}", version, e));
     }
 }