[Audit] handle-lifecycle XELOGKERNEL probes (cvar-gated)

New cvar `audit_handle_lifecycle` (Auditing group, default false).
When enabled, emits one-line XELOGKERNEL traces tagged AUDIT-HLC at:
  NtCreateEvent return, NtSetEvent entry, KeSetEvent entry,
  NtWaitForSingleObjectEx entry + completion,
  EmulateCPInterruptDPC entry.

Observation-only: zero-overhead when cvar off (single branch + flag
read). Intended for handle disambiguation between xenia-rs and
canary under the Wine cross-build oracle.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/xenia/kernel/kernel_flags.h

@@ -13,5 +13,6 @@
 
 DECLARE_bool(headless);
 DECLARE_bool(log_high_frequency_kernel_calls);
+DECLARE_bool(audit_handle_lifecycle);
 
 #endif  // XENIA_KERNEL_KERNEL_FLAGS_H_