fix(rust): resolve all clippy warnings treated as errors in CI

Fix 18 clippy errors across 7 files:
- lib.rs: change doc comment to regular comment (empty line after doc)
- arch_audit.rs: replace format!() with string literal, use is_none_or
- code_quality.rs: collapsible if, map_or → is_none_or
- commit.rs: collapsible match guard
- explore.rs: needless_range_loop → iterator enumerate
- skills.rs: map_or(false,...) → is_some_and
- semantic_search.rs: map_or → is_none_or, sort_by → sort_by_key,
  remove explicit type to avoid type_complexity

CI was failing with 'error: could not compile zesdex-infrastructure
due to 18 previous errors' at clippy step.

apps/infrastructure/src/tools/semantic_search.rs

@@ -286,7 +286,7 @@ impl SymbolIndex {
         let walker = ignore::Walk::new(path);
 
         // Pre-compile per-extension dispatch table.
-        let ext_dispatch: HashMap<&str, fn(&str, &str) -> Vec<CodeSymbol>> = HashMap::from([
+        let ext_dispatch = HashMap::from([
             ("rs", extract_rust as fn(&str, &str) -> Vec<CodeSymbol>),
             ("ts", extract_typescript as fn(&str, &str) -> Vec<CodeSymbol>),
             ("tsx", extract_typescript as fn(&str, &str) -> Vec<CodeSymbol>),
@@ -385,9 +385,9 @@ impl SymbolIndex {
             .symbols
             .iter()
             .filter(|s| {
-                language_filter.as_ref().map_or(true, |l| s.language == *l)
-                    && kind_filter.as_ref().map_or(true, |k| s.kind == *k)
-                    && file_filter.map_or(true, |f| s.file.contains(f))
+                language_filter.as_ref().is_none_or(|l| s.language == *l)
+                    && kind_filter.as_ref().is_none_or(|k| s.kind == *k)
+                    && file_filter.is_none_or(|f| s.file.contains(f))
             })
             .take(max_results)
             .collect();
@@ -401,7 +401,7 @@ impl SymbolIndex {
             *counts.entry(sym.language.clone()).or_default() += 1;
         }
         let mut sorted: Vec<(Language, usize)> = counts.into_iter().collect();
-        sorted.sort_by(|a, b| b.1.cmp(&a.1));
+        sorted.sort_by_key(|b| std::cmp::Reverse(b.1));
         sorted
     }
 
@@ -412,7 +412,7 @@ impl SymbolIndex {
             *counts.entry(sym.kind.clone()).or_default() += 1;
         }
         let mut sorted: Vec<(SymbolKind, usize)> = counts.into_iter().collect();
-        sorted.sort_by(|a, b| b.1.cmp(&a.1));
+        sorted.sort_by_key(|b| std::cmp::Reverse(b.1));
         sorted
     }
 }
@@ -1299,8 +1299,8 @@ impl Tool for SemanticSearch {
 
         let filtered: Vec<&&CodeSymbol> = results
             .iter()
-            .filter(|s| target_kind.as_ref().map_or(true, |k| s.kind == *k))
-            .filter(|s| target_lang.as_ref().map_or(true, |l| s.language == *l))
+            .filter(|s| target_kind.as_ref().is_none_or(|k| s.kind == *k))
+            .filter(|s| target_lang.as_ref().is_none_or(|l| s.language == *l))
             .take(max_results)
             .collect();