RFC 0001: Wire artifact card and library UI to real metadata APIs #56

Context

Issues #19 and #20 cover mocked UI slices, and PRs #26/#27 are still in review. After #48 and the library API work land, the UI needs to read real file/artifact metadata instead of local mock data.

Scope

Connect the artifact card and library list surfaces to the public file/artifact metadata API.

Acceptance criteria

• Uses exported file/artifact metadata types where practical.
• Lists user-owned files and generated artifacts from the API rather than hard-coded mock data.
• Shows loading, empty, error, deleted, and active states.
• Does not display raw object-store URLs or storage keys.
• Download/open actions use app-relative BharatCode file routes.
• Includes focused UI tests with mocked API responses.

Dependencies

• [codex] Add RFC 0001 artifact foundation contracts #48 for shared types.
• The file/artifact library API issue for real endpoints.

Non-goals

• No public sharing links yet.
• No production storage configuration.