Navbar Nav

{# Override of pydata_sphinx_theme's components/navbar-nav.html. PyData's default renders both top-level toctree items AND the configured external_links in one bar. For OpenCV we want ONLY this header nav (the tutorial module tree belongs in the left sidebar, not the header), so we render the external_links slot exclusively. These are NOT external links: conf.py declares them via the theme's external_links key only because that's the data slot for a custom header nav. Each entry is one of: * internal -> {"docname": "", "name": ...} resolved with pathto so the relative URL is correct at ANY page depth and points at the Sphinx-rendered page (landing, tutorials, module roots); * external -> {"url": "", "name": ..., "external": true} rendered verbatim and opened in a new tab (e.g. the Java docs, which have no Sphinx equivalent). Internal entries carry no target="_blank" / nav-external glyph since navigation never leaves the site. #}