refactor(ci): implement local build and test workflow (US-001)

Replace existing CI/CD workflow with new architecture that:
- Uses `docker` driver for local daemon access (no Docker Hub pulls)
- Builds base images first, then derived images (nginx, node)
- Consolidates Alpine builds into single job per version (8.1-8.4)
- Consolidates Debian builds into single job per type (dev/prod)
- Removes all push steps (to be added in subsequent user stories)
- Preserves all existing tests

Key changes:
- build-test-alpine: matrix on version, builds all 5 images per version
- build-test-debian: matrix on type, builds base + nginx per type
- No build-contexts needed - Docker resolves FROM locally
- Fixes supervisord test to use --version flag

This enables PRs to run CI without any Docker Hub access.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: fabriciojs