🧹 Refactor export function for improved code health

[undivisible]

🎯 What: The export function in src/store/export.rs was a long monolithic block of code that handled request validation, cursor validation, transaction orchestration, high water mark calculation, SQL querying, and result pagination/packing. I extracted these responsibilities into focused, single-purpose helper functions.

💡 Why: By extracting these distinct steps, we can significantly reduce the cognitive overhead required to understand what export is doing.

✅ Verification: I ran cargo check and cargo test to ensure that breaking up the function did not result in compile errors, logic errors, or failed functionality tests. All 104+ tests passed perfectly.

✨ Result: The export method now mostly serves as a clean orchestration pipeline making it easier to read and maintain.

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PR created automatically by Jules for task 12662369790428392060 started by @undivisible

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Note

Low Risk
Pure refactor of export orchestration with no intended logic or API changes; risk is limited to accidental behavior drift during extraction.

Overview
Breaks the monolithic MemoryDb::export method into focused helpers so the method is mostly orchestration.

Extracts validate_export_request, resolve_high_water_mark, validate_export_cursor, and pack_export_page. Behavior is unchanged: same validation, SQL query, pagination, and page packing.

^{Reviewed by Cursor Bugbot for commit 2dd39e4. Configure here.}

[google-labs-jules]

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[undivisible]

Superseded by the reviewed and merged integration in #22.

[google-labs-jules]

Superseded by the reviewed and merged integration in #22.

Understood. Acknowledging that this work is now obsolete and stopping work on this task.