Claude Code: fix blocking mkdir at module import in system_logger.py

Move mkdir operation to lazy initialization to prevent blocking
on module import, which was causing RUNNING_APP_STARTING hang.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

openclaw/.openclaw/core/system_logger.py

@@ -13,15 +13,17 @@ OPENCLAW_DIR = "/app/.openclaw"
 LOG_DIR = f"{OPENCLAW_DIR}/logs"
 SYSTEM_LOG = f"{LOG_DIR}/system.log"
 
-# Ensure log directory exists
-Path(LOG_DIR).mkdir(parents=True, exist_ok=True)
-
 # Thread lock for safe concurrent writes
 _lock = threading.Lock()
 
+def _ensure_log_dir():
+    """Ensure log directory exists (lazy, not at import time)."""
+    Path(LOG_DIR).mkdir(parents=True, exist_ok=True)
+
 
 def _write_log(message: str):
     """Internal: write a log entry with timestamp."""
+    _ensure_log_dir()
     with _lock:
         timestamp = datetime.utcnow().isoformat() + "+00:00"
         with open(SYSTEM_LOG, "a") as f: