Add GitHub Pages HTML report with interactive tabs

- Add --html and --html-output flags to unified_analysis.py
- Implement write_html_report() function generating tabbed HTML output
- Create docs/style.css with modern tab navigation and responsive table styling
- Create docs/script.js for tab switching with URL hash support
- Organize analysis sections into separate tabs:
  * Summary
  * Co-attendance Degree
  * Field Degree
  * Path Structure
  * Centrality
  * Clustering
  * Connected Components
- Preserve all explanatory text and data tables from Markdown version
- Generate docs/index.html ready for GitHub Pages deployment
- Add GitHub Actions workflow to auto-generate HTML report on push
- Configure workflow to commit updated HTML back to main branch

The HTML report maintains all functionality of the Markdown report while
providing an interactive tabbed interface suitable for web viewing. The
workflow automatically regenerates the report when source files change.

Author: stephen-rowan

.github/workflows/pages.yml

@@ -1,19 +1,25 @@
-name: Generate and Deploy Pages
+name: Generate HTML Report
 
 on:
   push:
     branches: [ main ]
     paths:
       - 'Graph Analysis/unified_analysis.py'
-      - '.github/workflows/pages.yml'
+      - 'reports/unified_analysis_report_explained.md'
   workflow_dispatch:  # Allow manual trigger
 
+permissions:
+  contents: write
+
 jobs:
-  generate-and-deploy:
+  generate-html:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v3
+    - name: Checkout repository
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0  # Fetch full history for proper git operations
 
     - name: Set up Python
       uses: actions/setup-python@v4
@@ -29,10 +35,16 @@ jobs:
       run: |
         python "Graph Analysis/unified_analysis.py" --html --html-output docs/index.html
     
-    - name: Deploy to GitHub Pages
-      uses: peaceiris/actions-gh-pages@v3
-      if: github.ref == 'refs/heads/main'
-      with:
-        github_token: ${{ secrets.GITHUB_TOKEN }}
-        publish_dir: ./docs
+    - name: Commit and push if changed
+      run: |
+        git config --local user.email "action@github.com"
+        git config --local user.name "GitHub Action"
+        git remote set-url origin https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git
+        git add docs/index.html
+        if git diff --staged --quiet; then
+          echo "No changes to commit"
+        else
+          git commit -m "Auto-update HTML report [skip ci]"
+          git push origin HEAD:main
+        fi