Implement tamper-evident audit logging and invoice correction features

- Introduced a new audit logging system that creates a tamper-evident chain of events in MongoDB.
- Added functions for appending audit events, ensuring index integrity, and verifying the audit chain.
- Implemented soft-delete functionality for inventory and borrowing records to comply with GoBD regulations.
- Added UI components for displaying invoice corrections and audit dashboard, including mismatch reporting.
- Created a CLI utility for verifying the integrity of the audit chain.
- Enhanced invoice management by preventing overwrites and allowing correction entries with reasons and optional deltas.

Web/verify_audit_chain.py

@@ -0,0 +1,31 @@
+#!/usr/bin/env python3
+"""CLI utility to verify the tamper-evident audit chain."""
+
+import json
+import sys
+
+from pymongo import MongoClient
+
+import settings as cfg
+import audit_log as al
+
+
+def main():
+    client = None
+    try:
+        client = MongoClient(cfg.MONGODB_HOST, cfg.MONGODB_PORT)
+        db = client[cfg.MONGODB_DB]
+        al.ensure_audit_indexes(db)
+        result = al.verify_audit_chain(db)
+        print(json.dumps(result, ensure_ascii=False, indent=2, default=str))
+        return 0 if result.get("ok") else 2
+    except Exception as exc:
+        print(json.dumps({"ok": False, "error": str(exc)}, ensure_ascii=False))
+        return 1
+    finally:
+        if client:
+            client.close()
+
+
+if __name__ == "__main__":
+    sys.exit(main())