Fix flaky integration test: ingested_chunks_have_correct_payload

[bug-ops]

Problem

The integration test zeph-memory::document_integration::ingested_chunks_have_correct_payload intermittently fails in CI with assert_eq!(all.len(), 1) returning 0.

Location: crates/zeph-memory/tests/document_integration.rs:174

CI run: https://github.com/bug-ops/zeph/actions/runs/22161593855/job/64079654265?pr=566

Root Cause

Race condition between Qdrant point insertion and subsequent scroll query in testcontainer environment. The scroll executes before the inserted point is visible.

Fix

Add a short retry loop or explicit wait after insertion before asserting scroll results.