Return the governing agreement (plain text). Served at this back-compatible endpoint for the consent-modal flows. Resolved in three distinct steps: (1) a workspace bound to a vertical that ships a gate document is served THAT document (e.g. a consulting Terms of Engagement); (2) a workspace bound to the default tenant is served that tenant's M&A terms; (3) NO workspace, an unknown UUID, or a vertical whose gate ships no template is served the EXCHANGE TERMS OF SERVICE — the terms of the exchange itself, independent of the verticals served, which keep governing the exchange when a vertical is unplugged. Rendered pages: GET /exchange-terms (exchange) and GET /tos (M&A platform). A mirror endpoint GET /api/tos/text is also provided.