fix: align test mutability and silence unused ptrace events var

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: vsilent

tests/collectors/event_enrichment_test.rs

@@ -143,7 +143,7 @@ fn test_timestamp_normalization() {
 
 #[test]
 fn test_enrichment_pipeline() {
-    let enricher = EventEnricher::new().expect("Failed to create enricher");
+    let mut enricher = EventEnricher::new().expect("Failed to create enricher");
     let mut event = SyscallEvent::new(1234, 1000, SyscallType::Execve, Utc::now());
 
     // Run full enrichment pipeline

tests/collectors/ptrace_capture_test.rs

@@ -20,7 +20,7 @@ mod linux_tests {
 
         std::thread::sleep(Duration::from_millis(100));
 
-        let events = monitor.poll_events();
+        let _events = monitor.poll_events();
 
         // Just verify monitor works without crashing
         assert!(true, "Monitor should handle ptrace detection gracefully");