fix: topology array reordering by subject order + unary inStackingContext

Topology array order mismatch (critical bug):
- CDP browser script iterates elements in document order (querySelectorAll),
  but solver accesses topology arrays by selector-resolution order.
- Fix: add subjectIds array to TopologyRecord tracking the backendNodeId
  at each document-order position; remapTopologyIds now reorders all 6
  topology arrays before remapping backendNodeIds to solver IDs.
- Fallback: when subjectIds is missing (cached pre-fix data), falls back
  to simple remap without reordering.

Unary inStackingContext compilation:
- compileCanonicalClauseToFormula treated inStackingContext as always binary,
  creating referenceBinding with undefined selector for unary assertions.
- Fix: add (inStackingContext && !clause.reference) to unaryPredicate/isUnary.

Hard test fixture (fixtures package):
- 29-element geometric fixture with 10 scenarios
- 57 assertions (54 spatial + 3 topology) all pass end-to-end

packages/imhotep-cdp/src/extractor.ts

@@ -546,6 +546,7 @@ export class CDPExtractor {
       scroll: [],
       clipping: [],
       topology: {
+        subjectIds: [],
         containingBlockOf: [],
         nearestPositionedAncestorOf: [],
         scrollContainerOf: [],
@@ -557,6 +558,9 @@ export class CDPExtractor {
       },
     }
 
+    // ... etc until the next empty topology at line ~964
+    
+
     if (request.requiredFacts.topology !== false && backendNodeIds.length > 0) {
       try {
         const { result, errors } = await extractTopology(session, backendNodeIds, subjectIds)
@@ -956,6 +960,7 @@ function createEmptySnapshot(request: ExtractorRequest): GeometryWorldSnapshot {
       fontWeight: [],
     },
     topology: {
+      subjectIds: [],
       containingBlockOf: [],
       nearestPositionedAncestorOf: [],
       scrollContainerOf: [],

packages/imhotep-cdp/src/topology.ts

@@ -42,6 +42,7 @@ export interface ClippingRecord {
  * Topology relation record.
  */
 export interface TopologyRecord {
+  subjectIds: number[]
   containingBlockOf: number[]
   nearestPositionedAncestorOf: number[]
   scrollContainerOf: number[]
@@ -83,6 +84,7 @@ export async function extractTopology(
         scroll: [],
         clipping: [],
         topology: {
+          subjectIds: [],
           containingBlockOf: [],
           nearestPositionedAncestorOf: [],
           scrollContainerOf: [],
@@ -138,6 +140,7 @@ export async function extractTopology(
         scroll: [],
         clipping: [],
         topology: {
+          subjectIds: [],
           containingBlockOf: [],
           nearestPositionedAncestorOf: [],
           scrollContainerOf: [],
@@ -269,6 +272,7 @@ export async function extractTopology(
           })
         }
 
+        results.topology.subjectIds.push(subjectId)
         results.topology.containingBlockOf.push(getId(getContainingBlock(el)))
         results.topology.nearestPositionedAncestorOf.push(getId(getNearestPositionedAncestor(el)))
         results.topology.scrollContainerOf.push(getId(getScrollContainer(el)))
@@ -301,6 +305,7 @@ export async function extractTopology(
       scroll: [],
       clipping: [],
       topology: {
+        subjectIds: [],
         containingBlockOf: [],
         nearestPositionedAncestorOf: [],
         scrollContainerOf: [],