Replaces nested column-major point lookups with a batched iterator that delegates to format-native traversal strategies. The implementation enforces a single pass per matrix type, using row-major iteration for sparse formats and eager collection for packed/columnar layouts while preserving original slot ordering. Memory allocation is optimized by removing `n_cols`-wide buffers in favor of per-row buffering or lazy iteration. Correctness tests verify iterator output against dense baselines across all supported layouts, and architecture documentation is updated to reflect the new format-agnostic query pattern.
Eric Coissac
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