ci: improve documentation sync check error message

Update check-docs job to provide clear step-by-step instructions
when generated docs are out of sync. The updated error message now
explicitly shows that builds must happen before doc generation:

1. pnpm install
2. pnpm build (generates .d.ts files needed for docs)
3. pnpm docs:generate (uses built declaration files)

This makes it clear that docs are generated from built TypeScript
declaration files, not directly from source.

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

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

Author: KyleAMathews

.github/workflows/pr.yml

@@ -90,3 +90,31 @@ jobs:
         run: |
           cd examples/react/projects
           pnpm build
+  check-docs:
+    name: Check Generated Docs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/[email protected]
+      - name: Setup Tools
+        uses: tanstack/config/.github/setup@main
+      - name: Build Packages
+        run: pnpm run build
+      - name: Generate Docs
+        run: pnpm docs:generate
+      - name: Check for changes
+        run: |
+          if [ -n "$(git status --porcelain)" ]; then
+            echo "Error: Generated docs are out of sync!"
+            echo ""
+            echo "Please run the following commands locally and commit the changes:"
+            echo "  1. pnpm install"
+            echo "  2. pnpm build"
+            echo "  3. pnpm docs:generate"
+            echo "  4. git add docs/"
+            echo "  5. git commit -m 'docs: regenerate API documentation'"
+            echo ""
+            echo "Files that need to be updated:"
+            git status --short
+            exit 1
+          fi