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/fts.rs

@@ -39,13 +39,13 @@ pub fn to_fts_query(raw: &str, mode: FtsQueryMode) -> String {
                 .split_whitespace()
                 .map(|token| {
                     // Check if token ends with * and the rest is alphanumeric
-                    if token.ends_with('*') {
-                        let stem = &token[..token.len() - 1];
-                        if !stem.is_empty() && stem.chars().all(|c| c.is_alphanumeric() || c == '_') {
-                            // Preserve prefix search: "stem"*
-                            let escaped = stem.replace('"', "\"\"");
-                            return format!("\"{}\"*", escaped);
-                        }
+                    if let Some(stem) = token.strip_suffix('*')
+                        && !stem.is_empty()
+                        && stem.chars().all(|c| c.is_alphanumeric() || c == '_')
+                    {
+                        // Preserve prefix search: "stem"*
+                        let escaped = stem.replace('"', "\"\"");
+                        return format!("\"{}\"*", escaped);
                     }
                     // Default: wrap in quotes, escape internal quotes
                     let escaped = token.replace('"', "\"\"");