Internal WABBLE roles — not studio business roles

This is a working feature, not a mock: messages and change requests submitted here call the Worker's /api/interchange and /api/change-requests routes. In this dev environment there is no D1 database attached, so submissions are accepted (202) but not persisted between requests — that becomes real storage once the beta environment's D1 binding is provisioned (a separate, not-yet-authorized step). App-owner / developer / admin / tester are the WABBLE team's own roles, distinct from the studio's Owner / Manager / Employee / Customer roles in the workspace.