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/best_practice/explore.rs

@@ -196,14 +196,14 @@ async fn run_explore_phase(
     turn_events: &Arc<Mutex<VecDeque<TurnEvent>>>,
 ) -> Result<String> {
     // ── 1. Emit Pending for all agents (appears instantly in workflow tab) ─
-    for i in 0..EXPLORE_AGENT_COUNT {
-        emit_pending(turn_events, EXPLORE_IDS[i], EXPLORE_LABELS[i]);
+    for (i, &id) in EXPLORE_IDS.iter().enumerate() {
+        emit_pending(turn_events, id, EXPLORE_LABELS[i]);
     }
 
     // ── 2. Prepare directives ───────────────────────────────────────────
     let mut directives: Vec<String> = Vec::with_capacity(EXPLORE_AGENT_COUNT);
-    for i in 0..EXPLORE_AGENT_COUNT {
-        let mut d = EXPLORE_DIRECTIVES[i].to_string();
+    for (i, &d) in EXPLORE_DIRECTIVES.iter().enumerate() {
+        let mut d = d.to_string();
         if i == 2 {
             d.push_str(&format!("\n\nThe user's current query is: \"{query}\""));
         }