py(deps[uv]) Bump gp-sphinx workspace pins to 0.0.1a13

why: Pull in the gp-sphinx 0.0.1a13 release (#24 in the workspace),
which lands the light-mode Pygments default (gp-sphinx-light palette
replacing the monokai-on-light fallback) and the theme-scoped argparse
highlighter. Without this bump the rendered docs keep serving
dark-on-light code blocks under the light theme and an ignored-theme
argparse palette.

what:
- pyproject.toml: gp-sphinx, sphinx-autodoc-api-style,
  sphinx-autodoc-fastmcp move 0.0.1a12 -> 0.0.1a13 in
  [dependency-groups] dev and docs.
- uv.lock regenerated; gp-sphinx workspace siblings co-resolved to
  0.0.1a13.

Author: tony

pyproject.toml

@@ -56,9 +56,9 @@ libtmux-mcp = "libtmux_mcp:main"
 [dependency-groups]
 dev = [
   # Docs
-  "gp-sphinx==0.0.1a12",
-  "sphinx-autodoc-api-style==0.0.1a12",
-  "sphinx-autodoc-fastmcp==0.0.1a12",
+  "gp-sphinx==0.0.1a13",
+  "sphinx-autodoc-api-style==0.0.1a13",
+  "sphinx-autodoc-fastmcp==0.0.1a13",
   "gp-libs",
   "sphinx-autobuild",
   # Testing
@@ -82,9 +82,9 @@ dev = [
 ]
 
 docs = [
-  "gp-sphinx==0.0.1a12",
-  "sphinx-autodoc-api-style==0.0.1a12",
-  "sphinx-autodoc-fastmcp==0.0.1a12",
+  "gp-sphinx==0.0.1a13",
+  "sphinx-autodoc-api-style==0.0.1a13",
+  "sphinx-autodoc-fastmcp==0.0.1a13",
   "gp-libs",
   "sphinx-autobuild",
 ]