FE-1308: restore main-based consent-card E2E with cloud #8010

FE-1308 live consent-card verification is blocked because the frontend implementation remains in draft PR https://github.com/Comfy-Org/ComfyUI_frontend/pull/16159 at `6c7346c8ae4d29eb181d9c98731d9d8a4d31a071`, based on `nathaniel/agent-panel-v1` rather than `main`. Cloud PR https://github.com/Comfy-Org/cloud/pull/8010 is deployed at `0c0d576f25d6d3ccfa87c6f21a41b62b2cb4c008`, but that backend preview cannot prove the card without a main-based frontend consumer.

Restore the deferred E2E by porting/retargeting the FE-1308 implementation to a main-based open PR, combining that exact frontend head with cloud #8010, and proving: Ask mode selected -> run prompt submitted -> consent card visible -> approval resumes submission. GPU inference is not required; reaching run submission is sufficient.

Expected-failure evidence from operator-7b on 2026-09-01: preview `/health` returned HTTP 200; Playwright could not launch on amp-worker-djzp because the fresh VM image lacks `libatk-1.0.so.0` after a user-local Chromium download. This environment gap must be fixed through IaC, not an in-place package install.