An Edit LLM writes only the fields it was thinking about. graphon requires a
handful per node type with no default, so `create_node{template-transform,
{title, template}}` produced a node the draft preflight refused -- and the
refusal killed the WHOLE repair batch, parking the session at
`edit.plan_approval` with an identical card on every approval (triage
`edit-branch-failure-2026-09-22` cause (b)).
Extend the node-type default registry to every type the Build/Edit/Fix agents
may create -- template-transform, code, http-request, variable-aggregator,
answer, question-classifier, if-else, tool -- each taken from the matching
`web/app/components/workflow/nodes/<type>/default.ts` and each cited alongside
the graphon field it covers. Add `default_config_or_empty`, a non-raising
lookup: a type the registry does not cover contributes no defaults rather than
aborting the edit that is creating it.
Merge those defaults UNDER the caller's config at `graph_ops._build_node`, the
one construction point every created node passes through. A field the caller
supplied always wins; only a missing one is filled. That covers Build, Edit and
Fix, `create_node` and `insert_between`, and the `filter_applicable` dry run,
so the dry run sees exactly the node the port will write.
Defaults fill MISSING required fields; a field that is present but WRONG stays
`graph_normalizers.heal_nodes_for_preflight`'s job.
Two editor-only keys are deliberately not copied. `_targetBranches` (if-else,
question-classifier) is frontend state the canvas regenerates from
`cases`/`classes`, which is also where `declared_branch_handles` reads handles
from. A caller-supplied `cases`/`classes` wins the merge while a default
`_targetBranches` would not, so shipping it would attach a stale branch list to
every Builder-created branch node.
Move the registry from `services/dify_builder/` to `core/dify_builder/`: it was
imported by `core/dify_builder/placeholder_agent.py`, against the constraint
that `core/` must not import from `services/`. The dependency now points the
legal way, and the module stays pure -- copy, typing and graphon only.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
