Generate Media Latent loses inputs and passed-through pipelines on reopen inside a subflow

Problem

When a Pipeline Builder → Create Noise Latent → Generate Media Latent chain lives inside a subflow (group) node, reopening the workflow breaks the graph:

• Generate Media Latent loses every input connection except the one coming from the pipeline node.
• Any pipeline that was routed through a node supporting pipeline passthrough (e.g. Create Noise Latent) is no longer registered on Generate Media Latent.

The saved workflow therefore does not round-trip: what the user wired up before saving is not what they get back after a reload, and they have to re-connect inputs by hand every time. The expected behaviour is that connections and passed-through pipelines survive save/reload identically to how they behave outside a subflow.

This is specific to the subflow group node — the same graph built at the top level of a workflow reloads correctly. Pipeline passthrough itself was previously broken and fixed for the non-subflow case; the subflow path appears not to have been covered by that fix.

Origin

Reported by Diogo Teixeira. Surface: Griptape Nodes editor, diffusers library nodes. Reproducible on every save + reload of an affected workflow.

Diogo also notes the Diffusers nodes in griptape-nodes-library-advanced-media are exposed to the same underlying behaviour, but that library ships no nodes that support pipeline passthrough, so the bug is close to impossible to trigger there in practice.

Impact

Any workflow that encapsulates a diffusers pipeline inside a subflow is effectively not persistable. Users lose their wiring on every reopen, which blocks using subflows to package reusable generation graphs — one of the main reasons to reach for a subflow in the first place.

Repro / evidence

1. Copy the layout of the image in the comments
2. Connect the text and integer inputs into the generate media latent
3. Save the workflow.
4. Reload/refresh the workflow.
   Observed: Generate Media Latent has dropped all inputs except the direct pipeline connection, and the passed-through pipeline is not registered. and looks like the example image in the comments
   Expected: the graph reloads exactly as saved, as it does when the same nodes sit outside a subflow.

Start by reproducing the Pipeline Builder → Create Noise Latent → Generate Media Latent chain inside a subflow, then save and reload it. Compare the subflow reload path with the top-level pipeline passthrough behavior described in the issue. Done means all input connections and passed-through pipelines are restored identically after reload.