feat: absorb cowork-complete-guide, ross-mike-workflows, vin-obsidian-workflows as labs

Each keeps its full history under its own directory. cowork-complete-guide's
static site is served at /cowork-complete-guide/ on the unified Pages site.
Also fixes stale miti99dev.github.io host references left from the org move.

.github/workflows/deploy-pages.yml

@@ -44,7 +44,7 @@ jobs:
         run: bun install --frozen-lockfile && bun run build
         working-directory: gstack
         env:
-          SITE_URL: https://miti99dev.github.io
+          SITE_URL: https://tiennm99dev.github.io
           SITE_BASE: /ai-coding-workflow-labs/gstack
 
       - name: Build cc4e-course quiz
@@ -65,6 +65,8 @@ jobs:
           cp -r cc4e-course/quiz-project/out _site/cc4e-course
           mkdir -p _site/advanced-claude-workflows
           cp advanced-claude-workflows/thumbnail.html _site/advanced-claude-workflows/index.html
+          mkdir -p _site/cowork-complete-guide
+          cp cowork-complete-guide/index.html cowork-complete-guide/pikachu-connect.html _site/cowork-complete-guide/
 
       - uses: actions/upload-pages-artifact@v3
         with: