Fix workflow to use file-based prompt building

Avoids YAML parsing issues with multiline strings.

Author: jamiew

.github/workflows/generate-site.yml

@@ -30,18 +30,24 @@ jobs:
       - name: Generate site with Claude API
         env:
           ANTHROPIC_API_KEY: ${{ secrets.CLAUDE_CODE_OAUTH_TOKEN }}
-          PROMPT_CONTENT: ${{ steps.prompt.outputs.content }}
         run: |
-          # Build the JSON request with jq to handle escaping
-          jq -n \
-            --arg model "claude-sonnet-4-20250514" \
-            --arg prompt "You are a web developer creating a GitHub Pages site.
+          # Build the prompt
+          cat > full_prompt.txt <<'EOF'
+You are a web developer creating a GitHub Pages site.
 
 Here are the requirements:
 
-$PROMPT_CONTENT
+EOF
+          cat docs/site-prompt.md >> full_prompt.txt
+          cat >> full_prompt.txt <<'EOF'
+
+Please generate a complete, production-ready index.html file following all requirements. Output ONLY the HTML code, no explanations or markdown code blocks.
+EOF
 
-Please generate a complete, production-ready index.html file following all requirements. Output ONLY the HTML code, no explanations or markdown code blocks." \
+          # Build JSON request
+          jq -n \
+            --arg model "claude-sonnet-4-20250514" \
+            --rawfile prompt full_prompt.txt \
             '{
               model: $model,
               max_tokens: 8192,