* refactor: rename `raw_investments_payload` to `raw_holdings_payload`
- Update references and models to use consistent naming.
- Adjust migrations, tests, and encryption setup accordingly.
* fix: improve safety when accessing raw_holdings_payload keys
- Use `dig` with safe navigation to prevent potential nil errors.
- Add support for decryption from the old column name `raw_investments_payload`.
- Adjust related methods and calculations for consistency.
---------
Co-authored-by: luckyPipewrench <luckypipewrench@proton.me>
Breaks our Plaid sync process out into more manageable classes. Notably, this moves the sync process to a distinct, 2-step flow:
1. Import stage - we first make API calls and import Plaid data to "mirror" tables
2. Processing stage - read the raw data, apply business rules, build internal domain models and sync balances
This provides several benefits:
- Plaid syncs can now be "replayed" without fetching API data again
- Mirror tables provide better audit and debugging capabilities
- Eliminates the "all or nothing" sync behavior that is currently in place, which is brittle
