Ensure Balance Tracker and Payment Finality

[sappenin]

We should put more thought into how to prove balance-tracker and payment finality in the Connector layer. E.g., potentially there is an infrastructure/deployment best-practice that we should identify. More research required here.

Potentially a doc on https://interledger4j.dev with recs:

Recommendations

1. Enable auditing in Postgres (every update should have a user).
2. Force all users to login with a personal identity.
3. Stream all packets to BigQuery to prevent
4. Put audit records into different namespace/db than transactional data.
5. Use external logging tool
6. Good fraud detection systems (potentially ML to detect irregularities).
7. Limits on settlement engine amounts.
8. Good network segmentation/isolation for various systems.
9. User-facing limits on withdrawals (amounts, waiting periods, etc).
10. Regular audits (external + internal)

Types of attack to consider

1. External Application layer
2. Internal infra compromise.
3. Sysadmin Attacks