feat(core): initial decnet_behave_core spec + tests

Shared observation envelope and schema contract. GPLv3.

core/pyproject.toml

@@ -0,0 +1,25 @@
+[build-system]
+requires = ["setuptools>=68", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "decnet-behave-core"
+version = "0.1.0"
+description = "BEHAVE shared observation envelope — schema contract used by BEHAVE-SHELL and BEHAVE-TEXT"
+requires-python = ">=3.11"
+license = { text = "GPL-3.0-or-later" }
+authors = [{ name = "ANTI" }]
+dependencies = ["pydantic>=2.6"]
+
+[project.optional-dependencies]
+dev = ["pytest>=8", "pytest-cov", "ruff"]
+
+[project.urls]
+"Source" = "https://git.resacachile.cl/anti/BEHAVE"
+
+[tool.setuptools.packages.find]
+include = ["decnet_behave_core*"]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+addopts = "-q --import-mode=importlib"