docs(css): border card-title code chips to match Furo prose chips

Furo applies its 1px chip border only to <code> inside a <p> (via the
SCSS `p & { border: ... }` rule). sphinx-design card titles are bare
<div class="sd-card-title">, so tool-name code chips in the tools /
prompts / resources grids were rendering as plain highlighted spans —
visually inconsistent with every other inline code chip on the site.

Add project-cards.css with one scoped rule extending the same
`var(--color-background-border)` border to code.literal and .sig-inline
inside .sd-card-title. Three pages affected (tools/*/ scope indices,
prompts, resources), zero markup changes, zero extension changes.

Author: tony

docs/_static/css/project-cards.css

@@ -0,0 +1,16 @@
+/* docs/_static/css/project-cards.css
+ *
+ * Scope: sphinx-design grid-item-card titles.
+ *
+ * Furo applies a 1px border to <code> chips only when they sit inside a
+ * paragraph (SCSS rule: `code.literal, .sig-inline { p & { border: 1px
+ * solid var(--color-background-border) } }`). Card titles are <div>s,
+ * not <p>s, so the border never lands -- the chip reads as a plain
+ * highlighted span instead of a proper code badge. Extend the same
+ * border to code chips in card titles so they match prose.
+ */
+
+.sd-card-title code.literal,
+.sd-card-title .sig-inline {
+  border: 1px solid var(--color-background-border);
+}

docs/conf.py

@@ -146,6 +146,7 @@ def setup(app: Sphinx) -> None:
     app.connect("autodoc-process-docstring", _convert_md_xrefs)
     app.add_js_file("js/prompt-copy.js", loading_method="defer")
     app.add_css_file("css/project-admonitions.css")
+    app.add_css_file("css/project-cards.css")
 
 
 globals().update(conf)