feat: apply validated graph update proposals

lib/graph/orchestrator.js

@@ -13,6 +13,7 @@ import {
   updateCaseRequestSchema,
 } from "./schema.js";
 import { buildInitialGraph, describeGraph } from "./builder.js";
+import { applyValidatedProposal } from "./apply-proposal.js";
 import { buildGraphUpdatePrompt } from "./prompt-builder.js";
 import { parseGraphUpdateProposal } from "./update-proposal.js";
 import {
@@ -180,6 +181,9 @@ async function updateCaseWithDependencies(body, dependencies = {}) {
     dependencies.buildGraphUpdatePrompt ?? buildGraphUpdatePrompt;
   const parseProposal =
     dependencies.parseGraphUpdateProposal ?? parseGraphUpdateProposal;
+  const applyProposalUpdate =
+    dependencies.applyValidatedProposal ?? applyValidatedProposal;
+  const shouldApplyProposal = dependencies.applyProposal === true;
 
   let modelName = null;
   let rawResponse;
@@ -238,6 +242,55 @@ async function updateCaseWithDependencies(body, dependencies = {}) {
     };
   }
 
+  if (shouldApplyProposal) {
+    const applicationResult = applyProposalUpdate({
+      situationGraph,
+      proposal: parsedProposal.proposal,
+    });
+
+    if (!applicationResult.success) {
+      return {
+        success: false,
+        stage: applicationResult.stage,
+        errors: applicationResult.errors,
+        diagnostics: {
+          promptVersion: promptVersion ?? null,
+          modelName,
+          responseDurationMs,
+          normalisationsApplied: parsedProposal.normalisationsApplied,
+          graphNodeCount: situationGraph.nodes.length,
+          graphEdgeCount: situationGraph.edges.length,
+        },
+        statusCode:
+          applicationResult.stage === "application" ||
+          applicationResult.stage === "result_validation"
+            ? 500
+            : 400,
+      };
+    }
+
+    return {
+      success: true,
+      stage: "update_applied",
+      updatedSituationGraph: applicationResult.updatedSituationGraph,
+      proposal: applicationResult.graphUpdate,
+      affectedNodeIds: applicationResult.affectedNodeIds,
+      resolvedUnknownNodeIds: applicationResult.resolvedUnknownNodeIds,
+      previousActiveUnknownNodeId:
+        applicationResult.previousActiveUnknownNodeId,
+      newActiveUnknownNodeId: applicationResult.newActiveUnknownNodeId,
+      changesApplied: applicationResult.changesApplied,
+      diagnostics: {
+        promptVersion: promptVersion ?? null,
+        modelName,
+        responseDurationMs,
+        normalisationsApplied: parsedProposal.normalisationsApplied,
+        graphNodeCount: applicationResult.updatedSituationGraph.nodes.length,
+        graphEdgeCount: applicationResult.updatedSituationGraph.edges.length,
+      },
+    };
+  }
+
   return {
     success: true,
     stage: "proposal_ready",