Downstream packagers (Debian) reported several problems with the tox manpage introduced in #1409. The RST title block and field-list metadata created a malformed top section where SYNOPSIS and other headings were indented under an unwanted parent section. Both man_pages config and the RST source generated their own AUTHOR and COPYRIGHT sections, producing duplicates. The project variable was never set in conf.py, causing "Project name not set" to appear in the manpage header. Finally, shared-data shipped the raw .rst source file rather than a compiled troff manpage, so tox man and man tox never worked.

The RST header block is removed since man_pages already handles the title, section, and description. The AUTHOR section is kept only in the RST (with the GitHub link) while clearing the man_pages authors list to prevent duplication. The COPYRIGHT section is removed from the RST since Sphinx generates one from conf.py. Setting project = name fixes the header. A hatch build hook using docutils now compiles the manpage to troff format at wheel-build time, so pip, pipx, and uv tool install all get a working tox.1 -- and tox man can find and symlink it correctly.

Fixes #3878