fix(ai): create_instance redo loses ntype/className — instantiation consumes them before reverse-capture (Pillar-2 Slice-2)

Context

Surfaced by #13306's redo e2e (test/playwright/e2e/NeuralLinkRedo.spec.mjs, branch fix/13306-nl-redo-e2e): a create_instance → undo → redo round-trip over the live bridge. Create + undo pass; redo fails:

{"redone":false,"reason":"redo-denied: create_instance: provide `className` or `ntype` to instantiate."}

So redo-of-a-created-component is non-functional: the re-dispatched forward-op has no ntype/className. (Undo works — this is redo-specific. The unit specs mock the transport, so they never exercised the live re-dispatch shape; the e2e did.)

Root cause (source-verified)

In src/ai/client/InstanceService.mjs#createInstance (~:92):

1. :94 createConfig = buildCreateInstanceConfig(...) — folds the resolved ntype/className INTO createConfig (e.g. {id, text, ntype: 'button'}).
2. :109 Neo.ntype(createConfig) → Neo.create(className, createConfig) → instance.construct(createConfig) — instantiation consumes the meta keys (ntype/className) off createConfig.
3. :126 the reverse is built from that same, now-mutated createConfig: buildCreateInstanceReverse({config: createConfig, ...}) → :286 forwardArgs = {config: safeSerialize(config)}.

safeSerialize preserves all object keys (it does NOT strip ntype), so the loss is upstream: createConfig no longer carries ntype/className by the time it's captured. On redo, handleRequest('create_instance', {config: {…no ntype…}, parentId}) → buildCreateInstanceConfig rejects with "provide className or ntype." The only mutation between the build (:94) and the capture (:126) is the instantiation at :109 — hence the cause.

The Fix

Snapshot the resolved config before instantiation consumes it, and capture from the snapshot:

const
    createConfig  = this.buildCreateInstanceConfig({className, config, ntype}),
    reverseConfig = {...createConfig};        // ntype/className intact, pre-instantiation
// …
const instance = createConfig.ntype ? Neo.ntype(createConfig) : Neo.create(createConfig);
// …
this.recordUndo(context, this.buildCreateInstanceReverse({config: reverseConfig, /* … */}));

Low-blast (capture-only; the create path itself is unchanged) and behavior-restoring (the redo contract — re-apply the undone create — is already documented; this fixes the broken implementation, so no new Contract Ledger per the contract-ledger.md bug-fix-restoring-documented-contract exclusion).

Acceptance Criteria

• redo of a create_instance restores the component to the live tree + DOM (the NeuralLinkRedo.spec e2e goes green).
• Unit coverage: the captured create_instance reverse forward-op retains ntype/className (a regression lock at the capture layer, not just e2e).
• No regression in the existing InstanceServiceUndo* / capture specs.

Related

• Blocks #13306 (the redo e2e proof — built, red on this bug; goes green with the fix).
• Pillar-2 undo/redo: Slice-parent #9848; epic #13012; sibling Slice-1 #13221 (undo, shipped). set_instance_properties redo is unaffected (fully cyclic); this is the create-replay leg.

Release classification: post-release Pillar-2 bug-fix (not v13-release-blocking) → boardless.

Authored by Claude Opus 4.8 (Claude Code), @neo-opus-vega (Vega).