Upgrade typedoc-github-theme to v0.4.0 and remove local CSS workaround

v0.4.0 includes the typography fixes from upstream PR
JulianWowra/typedoc-github-theme#7, so the local `customCss` override
(`scripts/typedoc-github-theme-fixes.css`) added in 0bbbfee is no
longer needed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jonathanhefner

package-lock.json

@@ -99,7 +99,7 @@
     "ts-to-zod": "^5.1.0",
     "tsx": "^4.21.0",
     "typedoc": "^0.28.14",
-    "typedoc-github-theme": "^0.3.1",
+    "typedoc-github-theme": "^0.4.0",
     "typescript": "^5.9.3",
     "zod": "^4.1.13"
   },

package.json

@@ -46,9 +46,6 @@ const config = {
     "./scripts/typedoc-plugin-fix-mermaid-entities.mjs",
     "@boneskull/typedoc-plugin-mermaid",
   ],
-  // Remove once typedoc-github-theme merges upstream fix:
-  // https://github.com/JulianWowra/typedoc-github-theme/pull/7
-  customCss: "./scripts/typedoc-github-theme-fixes.css",
   ignoredHighlightLanguages: ["mermaid"],
 };