fix: reconfigure logging to syslog after daemonize() instead of no-op basicConfig

After daemonize() redirects stderr to /dev/null, the existing StreamHandler
writes to /dev/null. logging.basicConfig() is a no-op when handlers are
already configured, so log messages are silently lost.

Replace the daemon block to:
1. Call daemonize() first
2. Explicitly remove existing handlers (pointing to /dev/null)
3. Add SysLogHandler pointing to /dev/log with fallback to UDP localhost:514
4. Log startup message to the new syslog handler

Removes redundant syslog.openlog() call which is no longer needed.

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

hbd/client/main.py

@@ -586,6 +586,41 @@ def daemonize(
     os.dup2(se.fileno(), sys.stderr.fileno())
 
 
+def _reconfigure_logging_for_daemon(log_level: int) -> None:
+    """Replace StreamHandlers (now writing to /dev/null) with a SysLogHandler."""
+    from logging.handlers import SysLogHandler
+
+    root = logging.getLogger()
+    for handler in root.handlers[:]:
+        root.removeHandler(handler)
+        handler.close()
+
+    try:
+        syslog_handler = SysLogHandler(
+            address="/dev/log",
+            facility=SysLogHandler.LOG_DAEMON,
+        )
+    except OSError:
+        syslog_handler = SysLogHandler(
+            address=("localhost", 514),
+            facility=SysLogHandler.LOG_DAEMON,
+        )
+        # Attach the fallback first so the warning reaches syslog
+        syslog_handler.setFormatter(
+            logging.Formatter("hbc[%(process)d]: %(name)s %(levelname)s: %(message)s")
+        )
+        root.addHandler(syslog_handler)
+        root.setLevel(log_level)
+        logging.warning("/dev/log not found, using syslog UDP localhost:514")
+        return
+
+    syslog_handler.setFormatter(
+        logging.Formatter("hbc[%(process)d]: %(name)s %(levelname)s: %(message)s")
+    )
+    root.addHandler(syslog_handler)
+    root.setLevel(log_level)
+
+
 def build_parser():
     """Build argument parser."""
     parser = argparse.ArgumentParser(
@@ -663,16 +698,9 @@ def main(argv=None):
     # Daemonize if requested
     if args.daemon:
         print("Daemonizing...")
-        import syslog
-        syslog.openlog("hbc", syslog.LOG_PID, syslog.LOG_DAEMON)
-        syslog.syslog(syslog.LOG_INFO, f"Starting heartbeat to {', '.join(args.hosts)}")
         daemonize()
-        
-        # Reconfigure logging for syslog
-        logging.basicConfig(
-            level=log_level,
-            format="hbc[%(process)d]: %(name)s %(levelname)s: %(message)s"
-        )
+        _reconfigure_logging_for_daemon(log_level)
+        logging.info(f"hbc starting, sending heartbeat to {', '.join(args.hosts)}")
     
     # Run async main
     try: