IncrementalIngestion_WithManyRecords_DeletesAllPreExistingChunks was hanging CI (killed after 5m28s+) due to 2500 individual SQLite UpsertAsync calls (~3ms each = ~8s locally, ~37× slower on CI).

Changes

• VectorStoreWriter.cs: Make MaxTopCount configuration-dependent via conditional compilation — 1_000 in Release, 10 in Debug — enabling pagination loop testing without large record sets:

  const int MaxTopCount =
  #if RELEASE
      1_000;
  #else
      10;
  #endif

• VectorStoreWriterTests.cs: Reduce record count from 2500 → 50. With MaxTopCount=10 in Debug, this still exercises 5 pagination iterations while eliminating the scaling concern.

Microsoft Reviewers: Open in CodeFlow