Higgsfield MCP unlimited trial can be active but unprovisioned

A Higgsfield MCP trial can report trial_status kind 'mcp_ultra_unlim' with status 'active' (show_plans_and_credits) while models_explore still returns unlim.available:false (remaining/expires_at null) and unlim_trial_in_mcp_active:false. In that state every use_unlim:true request fails with 'Unlimited generations aren't supported for <model>'. This happens for get_cost preflights and for real submissions, and with the exact resolution/quality configs the trial email advertises. Rejected unlim requests are not charged, so a real use_unlim:true submission is a safe definitive test. The error names internal model ids (nano_banana_2 -> nano_banana_flash, soul_2 -> text2image_soul_v2), which does not mean the model is wrong. Selecting the workspace (list_workspaces can show is_selected:false on the only workspace) does not fix it. It is a server-side provisioning fault for support, not a config issue on the client.