feat: add linear-state prefix cache batch and scheduler plumbing (5/n).

[yingxudeng]

Description

Related Issues

Change Type

• Bug fix
• New feature
• Performance improvement
• Refactor
• Documentation
• Test
• Build or CI

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Reviewer Notes

[yingxudeng]

[yingxudeng]

[Kang-Meng]

LGTM