chore: isolate docs from root workspace (#941)

Remove docs from root workspace packages since it already has its own
pnpm-workspace.yaml for independent Netlify builds. Move vitepress
peer dep rule to docs workspace config. Add docs lockfile for
reproducible installs.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: branchseer

.github/workflows/ci.yml

@@ -125,6 +125,9 @@ jobs:
 
       - uses: oxc-project/setup-node@fdbf0dfd334c4e6d56ceeb77d91c76339c2a0885 # v1.0.4
 
+      - name: Install docs dependencies
+        run: pnpm -C docs install --frozen-lockfile
+
       - name: Deduplicate dependencies
         run: pnpm dedupe --check
 
@@ -204,6 +207,9 @@ jobs:
 
       - uses: oxc-project/setup-node@fdbf0dfd334c4e6d56ceeb77d91c76339c2a0885 # v1.0.4
 
+      - name: Install docs dependencies
+        run: pnpm -C docs install --frozen-lockfile
+
       - uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
         with:
           name: rolldown-binaries