Generate Asset Access Token
Mint a per-user access token for the artifacts service, scoped to the calling user and workspace. The token authenticates direct calls to the artifacts service at the returned apiBaseUrl (https://link.octavehq.com in production — a public host; use the returned value, never a guessed hostname) — including asset creation/upload (multipart POST {apiBaseUrl}/api/v1/artifacts/), which has no /api/v2 proxy. Returns the plaintext token, which is shown ONLY here and on refresh — store it securely, it cannot be retrieved again. One token is active per user and workspace: calling again rotates it and invalidates the previous one, and other Octave surfaces acting as the same user (the in-app asset gallery, MCP tools) may rotate yours. Treat a 401 from the artifacts service as “generate again and retry once”.