refactor: improve log parser termination method in DB reset

- Replaced subprocess-based termination of the log parser with a Python-native approach using os and signal modules.
- Enhanced process handling to ensure proper termination of existing log parser instances before restarting.

This change improves reliability and compatibility across different environments.

dashboard/api/dashboard_api.py

@@ -116,9 +116,15 @@ def reset_db():
         db.commit()
 
     # 파서 프로세스 재시작 (entrypoint.sh의 백그라운드 프로세스)
-    import subprocess
-    # 기존 파서 종료
-    subprocess.run(["pkill", "-f", "log_parser.py"], capture_output=True)
+    import subprocess, os, signal
+    # 기존 파서 종료 (pkill 대신 Python-native 방식)
+    for proc_dir in os.listdir("/proc") if os.path.isdir("/proc") else []:
+        try:
+            cmdline = open(f"/proc/{proc_dir}/cmdline", "r").read()
+            if "log_parser.py" in cmdline and str(os.getpid()) != proc_dir:
+                os.kill(int(proc_dir), signal.SIGTERM)
+        except (ValueError, FileNotFoundError, PermissionError, ProcessLookupError):
+            pass
     # 새 파서 시작
     subprocess.Popen(["python", "log_parser.py"])