Add Periodic + Atexit Flush Support

[MuddyHope]

Currently, the CsvExporter only writes logs to disk when flush() is explicitly called. This can lead to lost logs if the program crashes or exits without a manual flush.

✅ Proposed Solution

Enhance CsvExporter to support both periodic flushing (every N seconds) and final flushing on program exit using atexit.

Benefits:

• Logs are flushed regularly in the background

• Safe shutdown with a final flush

• No loss of data even if the app exits or is interrupted

configure(
    export_type=ExportType.CSV,
    export_path="logs/query_log.csv",
    flush_interval_seconds=10  # flush every 10 seconds
)