✨ template: add LaTeX paper scaffold

[lalmei]

Summary

• Add an optional latex_paper prompt to render a paper folder.
• Include a LaTeX manuscript scaffold with sections, bibliography, figures folder, latexmk config, and Makefile targets.
• Document the new option and cover enabled and disabled rendering in template tests.

Verification

• make check
• uv run pytest -c=config/pytest.ini --no-cov tests/test_copier.py tests/test_template/test_ci.py::test_latex_paper_template_renders_paper_folder_only_when_enabled tests/test_template/test_ci.py::test_feature_enabled_template_keeps_optional_architecture_sections
• uv run pytest -c=config/pytest.ini --no-cov tests/test_template/test_ci.py::test_instantiated_template_format_check tests/test_template/test_ci.py::test_instantiated_template_lint tests/test_template/test_ci.py::test_instantiated_template_type_check

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This is part 2 of 4 in a stack made with GitButler:

•  4  ✨ template: add C++ Python bindings #109
•  3  ✨ template: add LaTeX paper scaffold #108 👈
•  2  ✨ template: add Meson C++ project template #107
•  1  🚚 docs: switch generated docs tooling to ProperDocs #106