feat(docker): add frontend live reload

[scotluns]

Why

This supports the cross-service hot-reload development workflow by letting frontend changes be verified quickly inside the local Compose stack instead of rebuilding the frontend image for each edit.

What Changed

• Adds a frontend dev Docker target.
• Installs dependencies with npm ci, seeds src, and runs Angular's dev server on port 80.
• Enables polling with CHOKIDAR_USEPOLLING=true and --poll 1000 so file changes synced by Compose Watch are detected reliably in Docker.

How To Verify

Start a developer-mode Compose stack with watch enabled from the deployment repo:

./docker/setup-workbench.sh --accept-defaults --dev-mode --taxii-server --instance-name live-reload-smoke
cd instances/live-reload-smoke
docker compose up --watch --build

Verify frontend reload:

$EDITOR ../../../attack-workbench-frontend/src/app/views/landing-page/landing-page.component.html +12

Temporarily change Explore to Explore Live. Confirm the frontend updates in the browser after reload/HMR, then revert the temporary text change.

Related PRs

• Deployment: feat(docker): add live reload workflow attack-workbench-deployment#6

Landing

Merge before the deployment live-reload PR.