feat: improve integration test times

[ChaoticTempest]

This makes our integration tests more performant.

• reduces the querying wait times since some were pretty big (sign had a 20s interval between queries).
• add in PregeneratedKeys which takes @jakmeier work on mpc fixture over for integration tests. This reduces our setup time by about 20s which is pretty good.
• our test_signature_basic went from 55-60s to now 30s from my measurement.

[Copilot]

Pull Request Overview

This PR optimizes integration test performance by introducing pregenerated keys to bypass the expensive MPC key generation protocol (20+ seconds). The changes add a new PregeneratedKeys enum with fixture data for 3 and 5 node configurations, inject these keys into storage during setup, and adjust various polling intervals to be more responsive.

• Introduces PregeneratedKeys configuration to load and manage pre-shared keys from fixture JSON files
• Injects pregenerated keys into storage before nodes start, enabling direct initialization with init_running to skip key generation
• Reduces polling intervals across wait functions from 3-20 seconds to 0.5-1 second for faster test feedback

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
integration-tests/src/cluster/spawner.rs	Adds PregeneratedKeys enum with fixture loading, key management methods, and integration into ClusterSpawner
integration-tests/src/lib.rs	Injects pregenerated keys into storage during setup and uses init_running contract call to skip key generation when keys are present
integration-tests/src/cluster/mod.rs	Reduces sleep duration from 3 seconds to 500ms in voting update
integration-tests/src/actions/wait_for.rs	Reduces polling delays from 20 seconds to 500ms-1s and increases max retry attempts for faster test responsiveness
integration-tests/src/actions/wait.rs	Reduces polling delays from 3-5 seconds to 500ms-1s across various wait functions

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[ChaoticTempest]

full integration test run went from 38-42mins to now 26mins

[jakmeier]

Wow, great improvement! Thanks for connecting the pregenerated data with integration tests.

[volovyks]

Impressive!