ci: include OpenVSCode web assets in GHCR image

[tariqsaidofficial]

Fixes the WPCodeSpace OpenVSCode GHCR image assembly so the published image includes browser web client assets.

Problem:

• The previously published image starts and responds over HTTP.
• Visual verification shows a blank page.
• Container logs show missing web assets:
  • /opt/openvscode-server/out/vs/code/browser/workbench/workbench.css
  • /opt/openvscode-server/out/nls.messages.js

Changes:

• Copy repository build output out/. into the Docker image context.
• Fail early if repository out/ is missing.
• Validate required web assets in the Docker context.
• Validate required web assets inside the built image.
• Extend smoke test to fail on missing asset logs.
• Add direct curl checks for required browser assets.

Preserved:

• No pull_request trigger.
• No latest tag.
• Immutable tags only.
• YAML-safe Dockerfile generation.
• Generated bundle guard.

Local validation:

• YAML parsed successfully.
• No pull_request or latest match.
• Workflow-only diff.
• git diff --check passed.