[Reliability] Pagination correctness issue — 2x over-fetch doesn't guarantee correct results

[daviddao]

Review Finding: 3b — MEDIUM

The cursor-based pagination re-sorts by createdAt after fetching by indexed_at:

// Fetch extra records to allow for re-sorting by createdAt
fetchLimit := first * 2

Over-fetching by 2x doesn't guarantee correctness — records could span page boundaries unpredictably. Requesting 20 records, fetching 50 and re-sorting can still miss records or produce duplicates.

Fix

Consider keyset pagination using (indexed_at, uri) composite cursor for deterministic, gap-free pagination.

From codebase review §3b