When a RabitqReformer trained with one total_bits is reused for an entity
configured with a different total_bits, the quantized data layout (ex_code
size) silently mismatches. This causes get_full_est() to interpret binary
quantization codes as floating-point factors, producing garbage distances
that sporadically drop search results.
Add an ex_bits() accessor to RabitqReformer and validate it against the
entity's ex_bits in HnswRabitqStreamer::open(), returning IndexError_Mismatch
on inconsistency. Fix the HNSWRabitqGeneral test to re-create a converter
and reformer with matching total_bits=2 for the third invocation. Add
TestExBitsMismatch to verify the mismatch is correctly rejected.
egolearner
23a1ef815e