feat(docs-site): add centralized version variable system

Add a version management system to acton-docs-site matching the pattern
from acton-service/acton-docs. This enables displaying the package
version in the logo and using Markdoc variables for dependency strings.

- Add src/lib/version.ts as single source of truth for VERSION
- Add src/lib/config.ts for site configuration (repository URLs)
- Add src/markdoc/config.js with version variables ($version.acton,
  $dep.ipc, $dep.ipcMessagepack)
- Update Logo.tsx to display version next to package name
- Update nodes.js fence transform to substitute variables in code blocks
- Update FAQ and IPC setup docs to use version variables

Author: rrrodzilla

acton-docs-site/src/app/docs/faq/page.md

@@ -78,7 +78,7 @@ Yes! Enable the `ipc` feature and use Unix Domain Sockets:
 
 ```toml
 [dependencies]
-acton-reactive = { version = "0.1", features = ["ipc"] }
+{% $dep.ipc %}
 ```
 
 See the [IPC Communication](/docs/ipc) guide for details.
@@ -401,7 +401,7 @@ If you're using IPC heavily, MessagePack is faster and smaller than JSON:
 
 ```toml
 [dependencies]
-acton-reactive = { version = "0.1", features = ["ipc-messagepack"] }
+{% $dep.ipcMessagepack %}
 ```
 
 ---

acton-docs-site/src/app/docs/ipc-setup/page.md

@@ -64,14 +64,14 @@ Add the `ipc` feature to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-acton-reactive = { version = "0.1", features = ["ipc"] }
+{% $dep.ipc %}
 ```
 
 For MessagePack serialization (smaller messages):
 
 ```toml
 [dependencies]
-acton-reactive = { version = "0.1", features = ["ipc-messagepack"] }
+{% $dep.ipcMessagepack %}
 ```
 
 ### Feature Comparison

acton-docs-site/src/components/Logo.tsx

@@ -1,3 +1,5 @@
+import { VERSION } from '@/lib/version'
+
 function LogomarkPaths() {
   return (
     <g fill="none" stroke="#38BDF8" strokeLinejoin="round" strokeWidth={2}>
@@ -19,7 +21,7 @@ export function Logomark(props: React.ComponentPropsWithoutRef<'svg'>) {
 
 export function Logo(props: React.ComponentPropsWithoutRef<'svg'>) {
   return (
-    <svg aria-hidden="true" viewBox="0 0 200 36" fill="none" {...props}>
+    <svg aria-hidden="true" viewBox="0 0 260 36" fill="none" {...props}>
       <LogomarkPaths />
       <text
         x="40"
@@ -32,6 +34,17 @@ export function Logo(props: React.ComponentPropsWithoutRef<'svg'>) {
       >
         acton-reactive
       </text>
+      <text
+        x="180"
+        y="24"
+        fill="currentColor"
+        fontFamily="ui-sans-serif, system-ui, sans-serif"
+        fontSize="14"
+        fontWeight="400"
+        opacity="0.6"
+      >
+        v{VERSION}
+      </text>
     </svg>
   )
 }

acton-docs-site/src/lib/config.ts

@@ -0,0 +1,17 @@
+/**
+ * Centralized configuration for site-wide constants
+ * This ensures DRY principle by having a single source of truth
+ */
+
+export const siteConfig = {
+  /**
+   * GitHub repository URL
+   * Used in: header links, hero CTA buttons, documentation links
+   */
+  repositoryUrl: 'https://github.com/govcraft/acton-reactive',
+
+  /**
+   * Repository name (derived from URL)
+   */
+  repositoryName: 'govcraft/acton-reactive',
+} as const

acton-docs-site/src/lib/version.ts

@@ -0,0 +1,5 @@
+/**
+ * Version information for acton-reactive
+ * This should match the version in the root Cargo.toml workspace.package.version
+ */
+export const VERSION = '0.7.0'

acton-docs-site/src/markdoc/config.js

@@ -0,0 +1,52 @@
+import nodes from './nodes.js'
+import tags from './tags.js'
+import { siteConfig } from '../lib/config'
+
+// Extract version from workspace Cargo.toml
+// This should be kept in sync with the workspace version
+const ACTON_VERSION = '0.7.0'
+
+// Helper function to build dependency string
+function buildDep(features) {
+  return `acton-reactive = { version = "${ACTON_VERSION}", features = [${features.map(f => `"${f}"`).join(', ')}] }`
+}
+
+const config = {
+  nodes,
+  tags,
+  functions: {
+    // Markdoc function to build cargo dependency with current version
+    dep: {
+      transform(parameters) {
+        const features = parameters[0] || []
+        if (typeof features === 'string') {
+          return `acton-reactive = { version = "${ACTON_VERSION}", features = ["${features}"] }`
+        }
+        return buildDep(features)
+      }
+    },
+    // Function to build GitHub URLs
+    githubUrl: {
+      transform(parameters) {
+        const path = parameters[0] || ''
+        return siteConfig.repositoryUrl + path
+      }
+    }
+  },
+  variables: {
+    version: {
+      acton: ACTON_VERSION,
+    },
+    github: {
+      repositoryUrl: siteConfig.repositoryUrl,
+      repositoryName: siteConfig.repositoryName,
+    },
+    dep: {
+      base: `acton-reactive = "${ACTON_VERSION}"`,
+      ipc: `acton-reactive = { version = "${ACTON_VERSION}", features = ["ipc"] }`,
+      ipcMessagepack: `acton-reactive = { version = "${ACTON_VERSION}", features = ["ipc-messagepack"] }`,
+    },
+  },
+}
+
+export default config

acton-docs-site/src/markdoc/nodes.js

@@ -56,6 +56,36 @@ const nodes = {
       language: {
         type: String,
       },
+      content: {
+        type: String,
+      },
+    },
+    transform(node, config) {
+      const attributes = node.transformAttributes(config)
+      const children = node.children[0]
+
+      // Get the fence content
+      let content = children?.attributes?.content || ''
+
+      // Replace {% $variable.path %} with actual values from config.variables
+      if (config.variables) {
+        content = content.replace(/\{%\s*\$([a-zA-Z0-9._]+)\s*%\}/g, (match, path) => {
+          const parts = path.split('.')
+          let value = config.variables
+
+          for (const part of parts) {
+            if (value && typeof value === 'object') {
+              value = value[part]
+            } else {
+              return match // Return original if path not found
+            }
+          }
+
+          return value !== undefined ? String(value) : match
+        })
+      }
+
+      return new Tag(this.render, attributes, [content])
     },
   },
 }