new: port the python template bodies to manifests

data/templates/python/__init__.py.tpl

@@ -0,0 +1,5 @@
+"""Placeholder for {name}, generated by `pkh new`."""
+
+
+def main() -> None:
+    print("Hello from {command}!")

data/templates/python/manifest.yml

@@ -1,9 +1,13 @@
-## The `python` template: a PEP 517 project built with pybuild. The logic
-## half — the pyproject.toml/setup.py probe, the skeleton bodies and the
-## Build-Depends/architecture resolution for existing projects (backend
-## package, pyproject presence, C-extension hints) — lives in
-## src/new/templates/python.rs; the lists below are the fresh-skeleton
-## baseline it starts from.
+## The `python` template: a PEP 517 project built with pybuild. The
+## skeleton bodies below are static data on the fresh-skeleton baseline
+## (the setuptools backend): the module directory and the console-script
+## entry point are named by the `{module_name}` placeholder python.rs
+## derives from the package name — dpkg names may carry `+`/`.` and may
+## start with a digit, none of which a Python module name may. The logic
+## half — the pyproject.toml/setup.py probe and the Build-Depends /
+## architecture resolution for existing projects (backend package,
+## pyproject presence, C-extension hints) — lives in
+## src/new/templates/python.rs.
 ##
 ## Schema: see src/new/templates/mod.rs.
 
@@ -18,4 +22,8 @@ build_depends:
   - python3-setuptools
 architecture: all
 rules_dh_line: "dh $@ --with python3 --buildsystem=pybuild"
-files: []
+files:
+  - path: pyproject.toml
+    template: pyproject.toml.tpl
+  - path: "{module_name}/__init__.py"
+    template: __init__.py.tpl

data/templates/python/pyproject.toml.tpl

@@ -0,0 +1,12 @@
+[build-system]
+requires = ["setuptools"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "{name}"
+version = "{upstream_version}"
+description = "{summary}"
+requires-python = ">=3.8"
+
+[project.scripts]
+{command} = "{module_name}:main"