py(deps[uv-sources]): override gp-sphinx workspace at local path for SEO branch

why: gp-sphinx 0.0.1a9 on PyPI still pulls in sphinxext-opengraph and
no sitemap generator. The seo-packages branch in
git-pull/gp-sphinx replaces sphinxext-opengraph with the lightweight
gp-opengraph (no matplotlib) and adds gp-sitemap. To exercise that
work end-to-end against libtmux-mcp's docs build before merge, point
[tool.uv.sources] at the sibling /home/d/work/python/gp-sphinx repo
so uv resolves gp-sphinx, gp-opengraph, and gp-sitemap from there
instead of the published wheels.
what:
- Add a temporary [tool.uv.sources] table pinning gp-sphinx,
  gp-opengraph, and gp-sitemap to ../gp-sphinx/packages/<name>
  (editable). uv auto-resolves the other gp-sphinx workspace
  members (sphinx-fonts, sphinx-gp-theme, sphinx-autodoc-typehints-gp)
  to their local paths via workspace discovery
- Refresh uv.lock: sphinxext-opengraph removed; gp-opengraph and
  gp-sitemap added
- Comment in pyproject.toml flags the override as temporary; drop
  once seo-packages merges and a release is tagged

Author: tony

pyproject.toml

@@ -109,6 +109,14 @@ lint = [
 requires = ["hatchling"]
 build-backend = "hatchling.build"
 
+# Temporary local overrides while the SEO packages are still on the
+# `seo-packages` branch of git-pull/gp-sphinx. Drop this table once the
+# branch is merged and a release is tagged on PyPI.
+[tool.uv.sources]
+gp-sphinx = { path = "../gp-sphinx/packages/gp-sphinx", editable = true }
+gp-opengraph = { path = "../gp-sphinx/packages/gp-opengraph", editable = true }
+gp-sitemap = { path = "../gp-sphinx/packages/gp-sitemap", editable = true }
+
 [tool.mypy]
 strict = true
 python_version = "3.10"