feat(wizard): produce fully startable EA2 flows

Reverse-engineered the EA2 runtime startability contract by diffing
pr_to_po_def (startable) against wizard-created drafts (500). Minimum
shape required:

  Parent flow (kind=definition, status=published)
  + Step flow (kind=definition, status=published, dispatch_kind=human)
  + View doc (kind=definition, status=active, layout={fields,layout:form})
  + Version doc (kind=definition, status=active)
  + defines edge: parent -> step (role=child)
  + defines edge: step -> step (role=dispatch self-edge)
  + defines edge: step -> view (role=presentation)
  + governs edge collection 'governs': version -> parent (role=governs)

wizardApi.ops gains: createView, createVersion, childEdge, dispatchEdge,
presentationEdge, governsEdge. createStepEdge renamed to childEdge to
reflect the actual EA2 role. Steps now create with status=published
(was draft) so they're visible to the runtime.

Wizard.handleStructureSave emits all of the above in two apply-batches
(creates then wires). Verified live: posted a probe flow with this
contract, /api/runtime/transactions returned 200 + a running
transaction with step_run_id.

src/lib/chatApi.ts

@@ -215,7 +215,7 @@ export const chatApi = {
     if (!created.ok) throw new Error(`sendMessage create ${created.status}`);
     const msg = await created.json();
 
-    const linkOps: BatchOperation[] = [wizardApi.ops.createStepEdge(threadKey, msg._key)];
+    const linkOps: BatchOperation[] = [wizardApi.ops.childEdge(threadKey, msg._key)];
     await fetch(`${api.config.baseUrl}/api/ea2/apply-batch`, {
       method: "POST",
       headers: authHeaders(),