chore: Store fee policies for all proposed orders

Background

The autopilot currently does not store fee policies for each order which is proposed for execution by solvers. This makes it difficult to exactly replicate the filtering and winner selection logic. Storing all fee policies for orders with at least one solution would resolve this.

Details

The post processing of auctions involves a step where fee policies are stored.

https://github.com/cowprotocol/services/blob/72d5cf4689d7b436c07224b4ad4813a6d29d9993/crates/autopilot/src/run_loop.rs#L552-L565

The code restricts to orders in ranked solutions, i.e. solutions which were not filtered out. I think that changing the implementation to use all() instead of ranked() could resolve this problem. This would make it consistent with how solutions themselves are stored.

Acceptance criteria

• store fee policies for all orders which are part of at least one proposed solution, for each auction
• update db docs

Start in crates/autopilot/src/run_loop.rs around lines 552-565 and inspect the auction post-processing step that stores fee policies. Compare the order selection used there with the solution storage path, then run the relevant autopilot or database tests. Done means fee policies are stored for every order in at least one proposed solution for each auction and the database documentation is updated.