denormalize graphql schema

[mariobassem]

currently, querying simple information from the postgres db requires multiple table joins, expensive calculations and have really bad performance. Hence, some data denormalization is needed, and if possible, doing the required calculations on the fly as events are reported.

[sameh-farouk]

I noticed that our processor DB didn't use indexes at all.
It is crucial to add database indexes to the entity fields on which one expects filtering and ordering.
I would look first into adding indexes to our schema as the lack of indices is the most common cause of slow API queries.

[sameh-farouk]

Splitting this into two concerns:

Denormalization — PR #132 has been stale since Oct 2023. The API surface change would affect downstream consumers (grid-proxy, dashboard, SDKs), and with the Hero Ledger migration underway, the effort isn't justified. Closing PR #132 and this issue for the denormalization part.

Indexes — The processor DB has no indexes on commonly filtered/ordered fields (nodeID, farmID, twinID, contractID, state). Only FK indexes from the initial TypeORM migration exist. Adding @index directives to schema.graphql is low effort and high impact for query performance. Tracked separately in #216.