readme: describe the space card in client-facing terms

docs: add leaderboard discovery tags to README front-matter

docs: link companion datasets in README front-matter

docs: add hf_oauth + apache-2.0 license to README front-matter

docs: rewrite Space README + About tab as declarative current state

docs: refresh stale status strings after org transfer

docs: refresh stale science/ migration target in space README

step 6 (A2): switch space to sdk:docker, install cadgenbench from private LeForge via GH_PAT build secret

step 3: gradio leaderboard scaffold

initial commit