vector-engine reproduce scripts

Requires: Linux, Python 3.12+, ~500 MiB free RAM for the ANN microbenches.

cd /path/to/2bzltl
python3 -m venv .venvs/vector-engine-reproduce
.venvs/vector-engine-reproduce/bin/pip install 'numpy==1.26.4' 'hnswlib==0.8.0'
cd post/db/vector-engine/reproduce
./run_exp_07_08.sh
./run_exp_11.sh
./exp_03_segment_lifecycle.sh   # exits 2 without Docker + MILVUS_URI

Keep the venv outside post/ (.venvs/…) so build_markdown.py does not pick up package LICENSE.md files.

exp_07_08 / exp_11 are hnswlib models used to illustrate Flat-as-gold and post-filter selectivity. They are not Milvus Segcore/Knowhere wall-clock numbers.