Update Node.js version to 22

Update to Node.js 22 now that @netlify/plugin-lighthouse has been removed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: bdougie

.nvmrc

@@ -1 +1 @@
-18
+22

netlify.toml

@@ -2,16 +2,16 @@
   command = "npm run build"
 
 [build.environment]
-  NODE_VERSION = "18"
+  NODE_VERSION = "22"
 
 [context.production.environment]
-  NODE_VERSION = "18"
+  NODE_VERSION = "22"
 
 [context.deploy-preview.environment]
-  NODE_VERSION = "18"
+  NODE_VERSION = "22"
 
 [context.branch-deploy.environment]
-  NODE_VERSION = "18"
+  NODE_VERSION = "22"
 
 # Explicitly define plugins to override UI configuration
 # This prevents the @netlify/plugin-lighthouse from running