Add external fault controls for validator scenarios

[bmuddha]

Outcome

Allow a scenario to stop MBV from observing a particular network result while the underlying base-chain operation continues.

For example, a test must be able to prove that a commit landed on base, then prevent MBV from receiving either the submission response or its confirmation.

Scope

Add optional RedSuite-owned HTTP/WebSocket proxies between a private ER and its base-chain endpoints.

Support holding and releasing selected requests, responses, and notifications; closing connections; and temporarily rejecting requests. Match operations using RPC method, account, or transaction signature as appropriate.

The scenario’s own base-chain client must bypass these proxies so it can independently verify execution. Reuse existing process restart controls. TCP replication fault controls are not needed.

Acceptance criteria

• A scenario can wait until a selected operation is intercepted, apply its fault, and explicitly restore traffic.
• Reports record which operation was intercepted and when it was held, released, or dropped.
• Unselected traffic passes through normally, and ordinary delay/disconnect tests do not fabricate account contents or slots.
• Cleanup closes proxy connections and releases pending work even when the scenario fails.
• A scenario cannot pass if its requested interception never occurred.