Create a new InfoSlides workspace and get its API key

Called with no credential, provisions a brand-new workspace on the free plan and returns its admin API key exactly once. ownerEmail must be an address you can open right now, never an invented one or a placeholder; your own is recommended, so you can verify it at once and then add the person with POST /v1/team/invitations. Adding a screen fails with EmailNotVerified until the address is verified: open the verification email, sign in once with Google or Microsoft using that address, or set a password. Accepts an optional source field (web, api, cli, mcp, muse) recording how the signup originated, and optional timeZone and locale (same values as PATCH /v1/tenant); otherwise the workspace starts on Atlantic/Reykjavik and is-IS. An agent should also send agent with its own product name (e.g. "Muse", "Instinct", at most 40 characters, plain text) — kept separate from source, which stays the fixed channel. Optionally send ownerName (the person's first name, at most 100 characters) so emails greet them by name instead of the workspace name; ask for it only when that is free, never invent one. Called with an admin API key instead, creates an additional workspace attached to that key owner's own account (ownerEmail must match the caller's own address) and returns that new workspace's own admin key — the recommended way to manage several workspaces under one identity is POST /v1/team/invitations to add teammates instead, one API key per workspace.