Publish CLAUDE.md snapshot at /CLAUDE.md, linked from footers

Serve it as text/plain on deploy so browsers display the raw text
instead of downloading; add .dockerignore so local image builds can't
ship stale _site or host node_modules.

.gitea/workflows/deploy.yaml

@@ -28,6 +28,10 @@ jobs:
         run: |
           apt-get update -qq && apt-get install -y -qq awscli > /dev/null
           aws s3 sync _site/ s3://${{ vars.S3_BUCKET }} --delete
+          # sync guesses text/markdown for .md, which Firefox downloads
+          # instead of displaying; text/plain shows the raw text in the tab
+          aws s3 cp _site/CLAUDE.md s3://${{ vars.S3_BUCKET }}/CLAUDE.md \
+            --content-type "text/plain; charset=utf-8"
 
       - name: Invalidate CloudFront
         if: vars.CF_DISTRIBUTION_ID != ''