ci: add comprehensive website CI/CD test suite

Removed old workflows:
- deploy.yml, eosim-sanity.yml, link-check.yml, nightly.yml, release.yml, weekly.yml

Added new website-focused CI/CD:

1. website-sanity.yml (on push/PR):
   - HTML W3C validation (html5validator)
   - Duplicate DOCTYPE detection (catches doubled files)
   - HTML structure validation (tag balance, unclosed divs)
   - Required files existence check (16 pages + CSS)
   - Meta tag validation (viewport, charset, title)
   - Internal link validation (href + src)
   - CSS syntax validation (brace balance, undefined vars, responsive breakpoints)
   - Mobile compatibility (viewport meta, hamburger menu, no fixed-width overflow)
   - Cross-page consistency (license, nav links)

2. website-performance.yml (on push/PR + weekly):
   - Lighthouse Desktop (6 key pages, thresholds: perf 70%, a11y/bp/seo 80%)
   - Lighthouse Mobile (4 key pages, thresholds: perf 50%, a11y/bp/seo 75%)
   - JSON result artifacts uploaded

3. website-e2e.yml (on push/PR):
   - Playwright responsive tests across 5 viewports (iPhone SE to 1080p)
   - Page load sanity (no JS errors, status < 400)
   - HTML structure (navbar + footer on every page)
   - Mobile horizontal overflow detection
   - Hamburger menu toggle verification
   - Desktop layout validation
   - Internal navigation link crawling
   - Interactive element testing (path switcher)
   - Visual sanity screenshots (30 captures: 5 viewports x 6 pages)
   - Screenshot artifacts uploaded

4. deploy.yml (on push to main):
   - Pre-deploy validation gate (required files, no duplicate DOCTYPE, link check)
   - GitHub Pages deployment only after validation passes

Author: srpatcha

.github/workflows/deploy.yml

@@ -1,5 +1,4 @@
 name: Deploy to GitHub Pages
-
 on:
   push:
     branches: [main]
@@ -15,61 +14,82 @@ concurrency:
   cancel-in-progress: true
 
 jobs:
-  build:
+  pre-deploy-checks:
+    name: Pre-Deploy Validation
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
 
-      - name: Validate HTML files exist
+      - name: Verify all required files exist and are non-empty
         run: |
-          for f in index.html getting-started.html kids.html hardware-lab.html flow.html \
-                   docs/index.html docs/eos.html docs/eboot.html docs/ebuild.html \
-                   docs/eai.html docs/eipc.html docs/eni.html docs/eosim.html \
-                   docs/eosuite.html docs/eostudio.html style.css; do
+          REQUIRED=(
+            index.html getting-started.html kids.html hardware-lab.html flow.html style.css
+            docs/index.html docs/eos.html docs/eboot.html docs/ebuild.html
+            docs/eai.html docs/eipc.html docs/eni.html docs/eosim.html
+            docs/eosuite.html docs/eostudio.html
+          )
+          EXIT=0
+          for f in "${REQUIRED[@]}"; do
             if [ ! -f "$f" ]; then
-              echo "ERROR: Missing $f"
-              exit 1
+              echo "FAIL: Missing $f"; EXIT=1
+            else
+              SIZE=$(stat -c%s "$f")
+              if [ "$SIZE" -lt 100 ]; then
+                echo "FAIL: $f is too small ($SIZE bytes)"; EXIT=1
+              else
+                echo "  OK: $f ($SIZE bytes)"
+              fi
             fi
-            SIZE=$(stat -c%s "$f" 2>/dev/null || stat -f%z "$f")
-            if [ "$SIZE" -lt 100 ]; then
-              echo "ERROR: $f is too small ($SIZE bytes)"
-              exit 1
+          done
+          exit $EXIT
+
+      - name: Check no duplicate DOCTYPE
+        run: |
+          EXIT=0
+          for f in $(find . -name '*.html' -not -path './.git/*' -not -path './node_modules/*'); do
+            COUNT=$(grep -c '<!DOCTYPE' "$f" 2>/dev/null || echo 0)
+            if [ "$COUNT" -gt 1 ]; then
+              echo "FAIL: $f has $COUNT <!DOCTYPE> (duplicated content!)"; EXIT=1
             fi
-            echo "OK: $f ($SIZE bytes)"
           done
+          exit $EXIT
 
-      - name: Check for broken internal links
+      - name: Check internal links
         run: |
           python3 -c "
-          import os, re
+          import os, re, sys
           errors = []
           for root, dirs, files in os.walk('.'):
-            if '.git' in root: continue
-            for f in files:
-              if not f.endswith('.html'): continue
-              path = os.path.join(root, f)
-              content = open(path).read()
-              for m in re.finditer(r'href=\"([^#][^:][^\"]*\.html)', content):
-                link = m.group(1)
-                target = os.path.normpath(os.path.join(os.path.dirname(path), link))
-                if not os.path.exists(target):
-                  errors.append(f'{path}: broken link to {link}')
+              if '.git' in root or 'node_modules' in root: continue
+              for f in files:
+                  if not f.endswith('.html'): continue
+                  path = os.path.join(root, f)
+                  content = open(path).read()
+                  for m in re.finditer(r'href=\"([^\"]*\.html)', content):
+                      href = m.group(1)
+                      if href.startswith(('http','#')): continue
+                      target = os.path.normpath(os.path.join(os.path.dirname(path), href.split('#')[0]))
+                      if not os.path.exists(target):
+                          errors.append(f'{path}: broken -> {href}')
           if errors:
-            for e in errors: print('ERROR:', e)
-            exit(1)
-          print(f'All internal links valid')
+              for e in errors: print('FAIL:', e)
+              sys.exit(1)
+          print('All links valid')
           "
 
-      - uses: actions/configure-pages@v4
-      - uses: actions/upload-pages-artifact@v3
-        with:
-          path: .
-
   deploy:
+    name: Deploy
+    needs: pre-deploy-checks
+    runs-on: ubuntu-latest
     environment:
       name: github-pages
-      url: ${{ github.event.repository.homepage }}
-    runs-on: ubuntu-latest
-    needs: build
+      url: ${{ steps.deployment.outputs.page_url }}
     steps:
-      - uses: actions/deploy-pages@v4
+      - uses: actions/checkout@v4
+      - uses: actions/configure-pages@v4
+      - uses: actions/upload-pages-artifact@v3
+        with:
+          path: .
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4