fix(ci): update deploy-docs workflow to use docs-linkcheck recipe

Change linkcheck → docs-linkcheck to match renamed justfile recipe.
Maintains consistency with multi-package monorepo naming pattern.

Author: cameronraysmith

.github/workflows/deploy-docs.yaml

@@ -74,7 +74,7 @@ jobs:
         run: nix develop -c just install
 
       - name: Validate documentation links
-        run: nix develop -c just linkcheck
+        run: nix develop -c just docs-linkcheck
 
       - name: Deploy to Cloudflare Workers
         id: deployment