fix: add deprecation warning to get_recent_logs method

The get_recent_logs method is deprecated in favor of journalctl.
Added a warning log when this method is called to help identify
code still using the deprecated method.

Addresses Copilot suggestion.

Signed-off-by: Scott R. Shinn <scott@atomicorp.com>

Author: atomicturtle

server/audit.py

@@ -71,4 +71,8 @@ def get_recent_logs(self, limit: int = 100) -> list:
         # This function is now deprecated in favor of journalctl
         # We return empty here to avoid breaking callers instantly, 
         # but the admin tool will be updated to fetch from journal.
+        self.logger.warning(
+            "AuditLogger.get_recent_logs is deprecated and returns an empty list; "
+            "use journalctl to access audit logs instead."
+        )
         return []