Resolves `AttributeError: 'DifferentialDiffusion' object has no attribute
'execute'` on older ComfyUI (<0.3.63) where the V3 schema migration has
not landed yet. The prior code called `.execute(model)[0]` directly,
breaking anyone still on the legacy `.apply(model)` API.
Introduce `modules/impact/utils.apply_differential_diffusion(model)`
which uses `hasattr` to pick the correct branch at runtime:
- `.execute` -> V3 classmethod (ComfyUI >= 0.3.63)
- `.apply` -> legacy instance method (older)
- otherwise -> AttributeError with upgrade guidance
Replace all 7 direct call sites (animatediff_nodes, core x2,
impact_pack x2, segs_nodes, segs_upscaler) with the helper. The
existing import guard in segs_upscaler is preserved; the helper's
deferred import means ImportError still propagates for very old
ComfyUI builds without `comfy_extras.nodes_differential_diffusion`.
Fixes GitHub issue #1177.
Also add an E2E test harness:
- docs/E2E_TEST_STRATEGY.md — isolated-launch workflow with
--disable-all-custom-nodes + --whitelist-custom-nodes, Playwright
smoke test, workflow execution via /prompt + /history + /view,
verification criteria, operational notes.
- tests/e2e_dd_compat.py — reference test that runs SEGSDetailer
with noise_mask_feather=20 on a real input image, asserting
status==success and non-zero pixel delta between input and paste
previews (proves the detailer loop and compat shim actually ran).
Dr.Lt.Data