Fix Docusaurus build by aligning @docusaurus/* versions

Dependabot bumped peripheral @docusaurus/* packages to 3.10.1 but left
core at 3.9.2, breaking the docs build. Align all @docusaurus/* on
3.10.1, add @docusaurus/faster (required by future.v4: true in 3.10),
and tighten react to ^19.2.6 to match react-dom. Group future
@docusaurus/* and react/react-dom bumps in dependabot.yml so they
upgrade together.

Author: andreogle

.github/dependabot.yml

@@ -17,6 +17,14 @@ updates:
       interval: 'weekly'
     cooldown:
       default-days: 3
+    groups:
+      docusaurus:
+        patterns:
+          - '@docusaurus/*'
+      react:
+        patterns:
+          - 'react'
+          - 'react-dom'
   - package-ecosystem: 'github-actions'
     directory: '/'
     schedule: