fix(confidence-engine): project unexplained transitions

docs/current-handoff.md

@@ -33,6 +33,12 @@
 - The read-back rule requires relationship type, endpoint direction, and description to agree. Provenance and interpretation-separation rules remain unchanged.
 - Deterministic tests prove the instruction exists, not that the model obeys it. No live call has tested this refinement; next restart point is live directional-integrity validation before broader repeatability testing.
 
+## Unexplained-transition projection coverage
+
+- Starting checkpoint: `e183914`. The latest one-call v0.5 validation emitted two reconstruction relationships: one directionally clean relationship projected, while the other (`r1`) was semantically/directionally incoherent and lost because it referenced an `unexplainedTransition` without graph projection.
+- `unexplainedTransitions` now project as unresolved transition nodes and register their source IDs for existing relationship projection; the relationship architecture itself was not redesigned.
+- The semantic coherence of live `r1` remains a separate unresolved reasoning issue; intervention-fit E was absent in that run and remains unresolved. No live validation has occurred after this deterministic fix.
+
 ## Current product architecture
 
 Three distinct routes, not a single page:

lib/graph/builder.js

@@ -204,6 +204,24 @@ export function buildInitialGraph(analysisData) {
     }
   }
 
+  // Unexplained transitions remain unresolved transition nodes
+  if (reconstruction.unexplainedTransitions) {
+    for (const trans of reconstruction.unexplainedTransitions) {
+      const label =
+        trans.description ||
+        `${trans.entity ?? "Unexplained transition"}: ${trans.previousState ?? "unknown"} → ${trans.currentState ?? "unknown"}`;
+      mapSourceId(trans.id, ensureNode(
+        label,
+        "transition",
+        "unknown",
+        trans.description || label,
+        null,
+        null,
+        trans.confidence || "low",
+      ));
+    }
+  }
+
   // Known transitions
   if (reconstruction.knownTransitions) {
     for (const trans of reconstruction.knownTransitions) {

tests/graph/builder.test.js

@@ -269,6 +269,51 @@ describe("buildInitialGraph", () => {
     }));
   });
 
+  it("projects relationships referencing unexplained transition source IDs", () => {
+    const reconstruction = {
+      ...makeReconstructionFixture(),
+      observedStates: [
+        { id: "obs-rate", description: "Complaint rate is not yet known", confidence: "high" },
+      ],
+      unexplainedTransitions: [
+        {
+          id: "ut-1",
+          description: "Support wait time increased without an explanation",
+          entity: "Support",
+          previousState: "2 hours",
+          currentState: "8 hours",
+          confidence: "medium",
+        },
+      ],
+      relationships: [{
+        id: "r-transition",
+        fromId: "obs-rate",
+        toId: "ut-1",
+        relationship: "depends_on",
+        description: "Understanding the rate depends on the unexplained transition.",
+        confidence: "medium",
+      }],
+    };
+
+    const result = buildInitialGraph({ reconstruction, evidence: [] });
+    const rateNode = result.nodes.find((node) => node.label === "Complaint rate is not yet known");
+    const transitionNode = result.nodes.find(
+      (node) => node.description === "Support wait time increased without an explanation",
+    );
+
+    expect(transitionNode).toMatchObject({
+      kind: "transition",
+      status: "unknown",
+      description: "Support wait time increased without an explanation",
+    });
+    expect(result.edges).toContainEqual(expect.objectContaining({
+      id: "e-rel-r-transition",
+      fromNodeId: rateNode.id,
+      toNodeId: transitionNode.id,
+      relationship: "depends_on",
+    }));
+  });
+
   it("skips relationships with invalid source IDs without creating substitute nodes", () => {
     const reconstruction = {
       ...makeReconstructionFixture(),