Add mermaid diagram support to documentation

Installed and configured @docusaurus/theme-mermaid to enable mermaid
diagrams in markdown files:

- Added @docusaurus/[email protected] (matching core version)
- Configured markdown.mermaid: true in docusaurus.config.ts
- Added mermaid theme to themes array

This enables the sequence diagram in the parameters-properties
documentation to render correctly, showing the execution flow and
variable lifespan throughout the build process.

Author: claude

docusaurus.config.ts

@@ -30,6 +30,13 @@ const config: Config = {
     locales: ['en'],
   },
 
+  // Enable mermaid diagrams in markdown
+  markdown: {
+    mermaid: true,
+  },
+
+  themes: ['@docusaurus/theme-mermaid'],
+
   presets: [
     [
       'classic',

package.json

@@ -17,6 +17,7 @@
   "dependencies": {
     "@docusaurus/core": "^3.8.1",
     "@docusaurus/preset-classic": "^3.8.1",
+    "@docusaurus/theme-mermaid": "3.8.1",
     "@mdx-js/react": "^3.0.0",
     "@signalwire/docusaurus-plugin-llms-txt": "^1.2.2",
     "clsx": "^2.0.0",