Fix: Restructure Dockerfile for cornucopia.owasp.org build context

[Mysterio-17]

Description

Fixes the Docker build failure in the ZAP website scan workflow. The Dockerfile was using repo-root-relative paths (cornucopia.owasp.org/...) while the build context was set to cornucopia.owasp.org, causing files like nginx.conf to not be found.

Changes

• Restructured Dockerfile to use paths relative to cornucopia.owasp.org build context
• Added a workflow step to copy source/ into the build context before the Docker build (needed for SvelteKit prerendering)
• Added .dockerignore to keep the build context lean
  Tested locally — Docker build completes and the container serves the website successfully.

AI Usage

Used AI assistance to debug the build context mismatch. Docker configuration and fix were verified manually with a local build and container test.

[Copilot]

Pull request overview

Fixes the cornucopia website Docker build in CI by aligning Dockerfile paths and build inputs with the cornucopia.owasp.org build context used by the ZAP nightly scan workflow.

Changes:

• Updated cornucopia.owasp.org/Dockerfile to use build-context-relative COPY paths and copy source/ to /source for prerendering.
• Added a workflow step to copy the repo-root source/ directory into the cornucopia.owasp.org build context before building the image.
• Added cornucopia.owasp.org/.dockerignore to reduce unnecessary build context contents.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
cornucopia.owasp.org/Dockerfile	Uses build-context-relative paths and ensures /source is present for SvelteKit prerendering during image build.
cornucopia.owasp.org/.dockerignore	Excludes common local/build artifacts and env files from the Docker build context.
.github/workflows/zap-nightly-scan-website.yml	Copies source/ into the build context so the website image can build successfully in the nightly ZAP scan.