Step 6 legacy archive

This archive keeps API/frontend/creation_knowledge assets that were removed from the formal mainline during the pipeline and app migration.

legacy_api/: old FastAPI entrypoints superseded by app/api.py and app/routes/*.
legacy_frontend/: old acquisition workbench build output from acquisition/web/app/dist.
legacy_creation_knowledge/: old top-level package kept for reference after reusable reader logic moved to decode_content/readers/* and formal API moved to app/*.
legacy_sqlite/: old local SQLite store for creation search runs/items. The formal state source is PostgreSQL through repository adapters.
legacy_acquisition/: old SQLite-coupled acquisition runner modules kept as migration evidence after platform adapters moved into acquisition/platforms/*.
legacy_scripts/: old SQLite/local JSON scripts replaced by formal scripts and repository-backed runners.
legacy_tests/: tests that assert local /data media-writing behavior. The formal media path now stores OSS/CDN URLs through acquisition media assets.