Add background task to export suspicious IPs to text file

- Implement export-malicious-ips task that queries distinct IPs flagged
    as is_suspicious from database and writes to exports/malicious_ips.txt
  - Add exports volume mount to docker-compose.yaml for host persistence
  - Update entrypoint.sh to fix ownership of exports directory for krawl user
  - Update Dockerfile to create /app/exports directory during build

Other tasks can be added by creating them in the tasks dir using the same setup as this task.
All tasks *MUST* include a TASK_CONFIG dict and a main method in the file to work correctly.

src/tasks/top_attacking_ips.py

@@ -0,0 +1,57 @@
+# tasks/export_malicious_ips.py
+
+import os
+from logger import get_app_logger
+from database import get_database
+from models import AccessLog
+from sqlalchemy import distinct
+
+app_logger = get_app_logger()
+
+# ----------------------
+# TASK CONFIG
+# ----------------------
+TASK_CONFIG = {
+    "name": "export-malicious-ips",
+    "cron": "*/5 * * * *",
+    "enabled": True,
+    "run_when_loaded": True
+}
+
+EXPORTS_DIR = "exports"
+OUTPUT_FILE = os.path.join(EXPORTS_DIR, "malicious_ips.txt")
+
+# ----------------------
+# TASK LOGIC
+# ----------------------
+def main():
+    """
+    Export all IPs flagged as suspicious to a text file.
+    TasksMaster will call this function based on the cron schedule.
+    """
+    task_name = TASK_CONFIG.get("name")
+    app_logger.info(f"[Background Task] {task_name} starting...")
+
+    try:
+        db = get_database()
+        session = db.session
+
+        # Query distinct suspicious IPs
+        results = session.query(distinct(AccessLog.ip)).filter(
+            AccessLog.is_suspicious == True
+        ).all()
+
+        # Ensure exports directory exists
+        os.makedirs(EXPORTS_DIR, exist_ok=True)
+
+        # Write IPs to file (one per line)
+        with open(OUTPUT_FILE, 'w') as f:
+            for (ip,) in results:
+                f.write(f"{ip}\n")
+
+        app_logger.info(f"[Background Task] {task_name} exported {len(results)} IPs to {OUTPUT_FILE}")
+
+    except Exception as e:
+        app_logger.error(f"[Background Task] {task_name} failed: {e}")
+    finally:
+        db.close_session()