test(driver): cover deadline call sites

[aspnxdd]

Description

Adds driver deadline tests.

Fixes #4495

Changes

• Expired solver deadline skips /solve.
• Post-processing stops when time runs out.
• Settlement fails after the submission deadline.

How to test

cargo nextest run -p driver 'tests::cases::deadline::' --run-ignored ignored-only

[github-actions]

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[aspnxdd]

I have read the CLA Document and I hereby sign the CLA

[aspnxdd]

recheck

[gemini-code-assist]

Code Review

This pull request introduces a new test suite for deadline-related scenarios, including expired solver deadlines, post-processing timeouts, and expired settlement submission deadlines. To support these tests, the test setup framework was updated to allow configuring a post-processing concurrency limit and custom deadline offsets. Additionally, the tracking of solve requests in the test solver was refactored from a boolean flag to an atomic counter to accurately count and assert the number of requests. No critical issues were identified in the review.

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[gemini-code-assist]

No critical issues found

References

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