Merge branch 'next/zero-norm-unvector-door'

# Conflicts:
#	src/hnsw/hnswIndex.ts

src/hnsw/hnswIndex.ts

@@ -10,7 +10,7 @@ import {
   Vector,
   VectorDocument
 } from '../coreTypes.js'
-import { euclideanDistance, calculateDistancesBatch } from '../utils/index.js'
+import { euclideanDistance, calculateDistancesBatch, isZeroNormVector } from '../utils/index.js'
 import type { BaseStorage } from '../storage/baseStorage.js'
 import { getGlobalCache, UnifiedCache } from '../utils/unifiedCache.js'
 import { prodLog } from '../utils/logger.js'
@@ -1834,10 +1834,24 @@ export class JsHnswVectorIndex implements VectorIndexProvider {
         // Process all nouns at once
         for (const nounData of result.items) {
           try {
-            if (!nounData.vector || nounData.vector.length === 0) {
+            if (!Array.isArray(nounData.vector) || nounData.vector.length === 0) {
               skippedUnvectored++
               continue
             }
+            // THE ZERO-NORM LAW — bulk-rebuild leg: a persisted zero-norm
+            // vector (a pre-10.4.2 row the canonical write has not yet
+            // normalized) must never enter the index either, mirroring the
+            // belt AddToVectorIndexOperation enforces on the live write path.
+            // Only the canonical vector is authoritative here — persisted
+            // HNSW graph metadata (level/connections) can outlive an unvector.
+            if (isZeroNormVector(nounData.vector)) {
+              prodLog.warn(
+                `[HNSW] rebuild(): skipping entity ${nounData.id} — persisted vector is ` +
+                  `zero-norm (a zero-norm vector is not a vector and never crosses an ` +
+                  `engine boundary)`
+              )
+              continue
+            }
 
             // Restore the pinned dimension from the first real vector this
             // rebuild loads. `addItem`/`updateItem` only pin `this.dimension`