feat(toolkit): ship macro_lactone_toolkit package

Unify macrolactone detection, numbering, fragmentation, and
splicing under the installable macro_lactone_toolkit package.

- replace legacy src.* modules with the new package layout
- add analyze/number/fragment CLI entrypoints and pixi tasks
- migrate tests, README, and scripts to the new package API

pixi.toml

@@ -1,24 +1,23 @@
 [workspace]
 authors = ["hotwa <pylyzeng@gmail.com>"]
 channels = ["conda-forge"]
-name = "macro_split"
-platforms = ["linux-64"]
+name = "macro_lactone_toolkit"
+platforms = ["osx-arm64", "linux-64"]
 version = "0.1.0"
 
 [tasks]
+test = "pytest"
+lint = "python -m compileall src"
+smoke-import = "python -c \"import macro_lactone_toolkit\""
+macro-lactone-toolkit = "python -m macro_lactone_toolkit.cli"
 
 [dependencies]
+python = "3.12.*"
+pip = ">=24,<26"
+pytest = ">=8.3,<9"
 rdkit = ">=2025.9.1,<2026"
 pandas = ">=2.3.3,<3"
 numpy = ">=2.3.4,<3"
-matplotlib = ">=3.10.7,<4"
-seaborn = ">=0.13.2,<0.14"
-jupyter = ">=1.1.1,<2"
-tqdm = ">=4.67.1,<5"
-mkdocs = ">=1.6.1,<2"
-mkdocs-material = ">=9.6.23,<10"
-mkdocstrings = ">=0.30.1,<0.31"
-mkdocstrings-python = ">=1.18.2,<2"
 
 [pypi-dependencies]
-dataclasses-json = ">=0.6.7, <0.7"
+macro_lactone_toolkit = { path = ".", editable = true }