Produce a concrete, reviewable breakdown of the work into small, safe, incremental refactor tickets that can be estimated, prioritized, and executed independently.

Scope:

• Identify the current checkpoint function’s (__checkpoint_db_internal) high-level responsibilities and major code paths.
• Propose a set of incremental refactor steps that reduce complexity without changing behavior.
• Create one follow-on JIRA ticket per step with a clear objective and acceptance criteria.

Non-goals:

• Implementing refactors or behavior changes in this ticket.
• Large-scale redesign unless explicitly called out as a separate proposal ticket.