docs: add live screenshot

feat: add Gradio HF Space wrapper — text-to-embedding UI

docs: comprehensive README — architecture, API, performance, MLOps features, portfolio context

fix: hardcode lowercase owner for GHCR compatibility

fix: standalone repo paths, lowercase GHCR owner, remove monorepo artifacts

feat: embedding service — bge-small-en-v1.5, FastAPI, Prometheus, Docker, CI/CD