feat: surface new unknowns after graph updates

lib/graph/schema.js

@@ -101,11 +101,22 @@ const graphUpdateNodeChangeSchema = z.object({
   nodeId: z.string().min(1),
   previousStatus: z.enum(Object.values(SituationStatus)).nullable().optional(),
   newStatus: z.enum(Object.values(SituationStatus)).nullable().optional(),
-  previousValue: z.union([z.string(), z.number(), z.null()]).nullable().optional(),
+  previousValue: z
+    .union([z.string(), z.number(), z.null()])
+    .nullable()
+    .optional(),
   newValue: z.union([z.string(), z.number(), z.null()]).nullable().optional(),
   reason: z.string().min(1),
 });
 
+export const selectedQuestionSchema = z
+  .object({
+    nodeId: z.string().min(1),
+    question: z.string().min(1),
+    reason: z.string().min(1),
+  })
+  .strict();
+
 export const graphUpdateSchema = z.object({
   addedNodes: z.array(situationNodeSchema).default([]),
   updatedNodes: z.array(graphUpdateNodeChangeSchema).default([]),
@@ -113,6 +124,7 @@ export const graphUpdateSchema = z.object({
   removedEdgeIds: z.array(z.string()).default([]),
   resolvedUnknownNodeIds: z.array(z.string()).default([]),
   affectedNodeIds: z.array(z.string()).default([]),
+  selectedQuestion: selectedQuestionSchema.nullable().default(null),
 });
 
 /** @typedef {z.infer<typeof graphUpdateSchema>} GraphUpdate */
@@ -169,7 +181,9 @@ export function makeNode(opts) {
 /** Create a minimal valid edge — used in tests and fixtures */
 export function makeEdge(opts) {
   return situationEdgeSchema.parse({
-    id: opts.id || "e" + opts.fromNodeId.slice(0,3) + "-" + opts.toNodeId.slice(0,3),
+    id:
+      opts.id ||
+      "e" + opts.fromNodeId.slice(0, 3) + "-" + opts.toNodeId.slice(0, 3),
     fromNodeId: opts.fromNodeId,
     toNodeId: opts.toNodeId,
     relationship: opts.relationship ?? "supports",