PRODAM ntthal WASM: source, build inputs, and provenance

Primer3 upstream https://github.com/primer3-org/primer3
Primer3 release v2.6.1 commit 7f9f17d6012f404e83bbf0f931a4d06eb4af465b.
Included original Primer3 src and upstream LICENSE. The ntthal compiler inputs
are thal_main.c, thal.c, thal_parameters.c, and src/primer3_config/.
Emscripten SDK 3.1.61: https://github.com/emscripten-core/emsdk
emsdk tag 3.1.61 commit ca7b40ae222a2d8763b6ac845388744b0e57cfb7.
The builder used releases-28e4a74b579b4157bda5fc34f23c7d3905a8bd6c.
Install and activate that SDK in an emsdk/ directory beside build-ntthal.sh,
then run bash build-ntthal.sh; no sequence data is required for the build.
WASM SHA-256 a4a94bb26613a0e12af934e5a955460b9b52f387d5046e36fdeaa13255f25701
Generated glue SHA-256 1d66db326eaad0765d9058b62358b9f90bbf5164116390d66276861d574061aa
Two builds in the original directory produced those exact matching hashes.
Primer3 upstream states GPL v2 or later; its source LICENSE and individual
source-file notices are included. Downstream integrated application and
third-party license obligations should be reviewed separately.
The test reference is generated with primer3-py 2.2.0; no sequence from a
research project is included or used.
