refactor(8.0): rename HNSWIndex class → JsHnswVectorIndex (scaffold step 3)

Step 3 of the brainy 8.0 rename scaffolding. The class name now matches
its role: the JS HNSW implementation of the VectorIndexProvider contract.
Per planning § 2.3: this is NOT cosmetic — leaving HNSWIndex when the
public contract is VectorIndexProvider creates a confusing read at the
implementation layer.

CHANGES

Repo-wide mechanical rename: HNSWIndex → JsHnswVectorIndex across 52
references in src/ + 5 references in tests/ via sed. Class declaration,
imports, JSDoc, comments, and identifiers all updated.

src/index.ts
- Primary public export: JsHnswVectorIndex (the new name).
- Backwards-compat alias: `export const HNSWIndex = JsHnswVectorIndex`
  with @deprecated note. Removed in the final 8.0 cleanup commit.

NO-OP scope

No behavioural change. The class is exactly the same; only the name
moved. Tests + build green.

VERIFICATION

- npx tsc --noEmit: clean
- npm test: 1468 / 1468 unit

src/hnsw/hnswIndex.ts

@@ -31,10 +31,10 @@ const DEFAULT_CONFIG: HNSWConfig = {
 
 /**
  * Implements {@link VectorIndexProvider}: the vector-index surface Brainy calls
- * on whatever the `'vector'` factory returns (its own `HNSWIndex`, or a native
+ * on whatever the `'vector'` factory returns (its own `JsHnswVectorIndex`, or a native
  * acceleration provider).
  */
-export class HNSWIndex implements VectorIndexProvider {
+export class JsHnswVectorIndex implements VectorIndexProvider {
   private nouns: Map<string, HNSWNoun> = new Map()
   private entryPointId: string | null = null
   private maxLevel = 0
@@ -71,7 +71,7 @@ export class HNSWIndex implements VectorIndexProvider {
   // COW (Copy-on-Write) support
   private cowEnabled: boolean = false
   private cowModifiedNodes: Set<string> = new Set()
-  private cowParent: HNSWIndex | null = null
+  private cowParent: JsHnswVectorIndex | null = null
 
   // Deferred HNSW persistence for cloud storage performance
   // In deferred mode, HNSW connections are only persisted on flush/close
@@ -130,7 +130,7 @@ export class HNSWIndex implements VectorIndexProvider {
    * Lifecycle: brainy.ts wires this after plugin activation when (a) the
    * `vectorStore:mmap` provider is registered AND (b) the storage adapter
    * resolves a real local path via `getBinaryBlobPath()`. Cloud adapters
-   * leave it null; HNSWIndex's behaviour is then identical to pre-2.4.0.
+   * leave it null; JsHnswVectorIndex's behaviour is then identical to pre-2.4.0.
    */
   public setVectorBackend(backend: MmapVectorBackend | null): void {
     this.vectorBackend = backend
@@ -340,10 +340,10 @@ export class HNSWIndex implements VectorIndexProvider {
    *
    * @example
    * ```typescript
-   * const parent = new HNSWIndex(config)
+   * const parent = new JsHnswVectorIndex(config)
    * // ... parent has 1M nodes ...
    *
-   * const fork = new HNSWIndex(config)
+   * const fork = new JsHnswVectorIndex(config)
    * fork.enableCOW(parent) // <10ms - instant!
    *
    * // Reads share data
@@ -353,7 +353,7 @@ export class HNSWIndex implements VectorIndexProvider {
    * await fork.addItem(newItem) // Deep copies only modified nodes
    * ```
    */
-  public enableCOW(parent: HNSWIndex): void {
+  public enableCOW(parent: JsHnswVectorIndex): void {
     this.cowEnabled = true
     this.cowParent = parent
 

src/hnsw/mmapVectorBackend.ts

@@ -1,10 +1,10 @@
 /**
  * @module hnsw/mmapVectorBackend
- * @description Disk-resident vector cache backing HNSWIndex, wrapping the
+ * @description Disk-resident vector cache backing JsHnswVectorIndex, wrapping the
  * `vectorStore:mmap` provider (cortex's NativeMmapVectorStore in production).
  *
  * **Why this exists.** Brainy's per-entity vector storage hits two ceilings as
- * datasets grow: (1) every `HNSWIndex.preloadVectors` does a sequential
+ * datasets grow: (1) every `JsHnswVectorIndex.preloadVectors` does a sequential
  * `storage.getNounVector` per id (no batch), and (2) cloud and FS storage both
  * serialize each vector through JSON / msgpack, blocking zero-copy reads. An
  * mmap-backed single-file vector store, addressed by the stable int from
@@ -20,7 +20,7 @@
  *
  * **Local-FS only in 2.4.0.** Activated when the storage adapter exposes a
  * real local path via `getBinaryBlobPath()`. Cloud adapters (S3 / R2 / GCS)
- * return null and the backend is not constructed, so HNSWIndex falls back to
+ * return null and the backend is not constructed, so JsHnswVectorIndex falls back to
  * the existing per-entity read path. Chunked vector segments for remote
  * storage are the planned 2.4.0 #2 follow-up.
  */
@@ -38,7 +38,7 @@ import type {
  * @description Bridge between brainy's UUID-keyed vector API and cortex's
  * int-slot mmap vector store. Translates UUIDs to stable int slots via the
  * `EntityIdMapper`, grows the file on demand, and handles read misses by
- * surfacing `null` (HNSWIndex's caller does the lazy storage fallback +
+ * surfacing `null` (JsHnswVectorIndex's caller does the lazy storage fallback +
  * write-back). The class never touches per-entity storage directly — it owns
  * only the mmap layer.
  */

src/hnsw/typeAwareHNSWIndex.ts

@@ -7,13 +7,13 @@
  * - Storage: Already type-first from Phase 1a
  *
  * Architecture:
- * - One HNSWIndex per NounType (42 total)
+ * - One JsHnswVectorIndex per NounType (42 total)
  * - Lazy initialization (indexes created on first use)
  * - Type routing for optimal performance
  * - Falls back to multi-type search when type unknown
  */
 
-import { HNSWIndex } from './hnswIndex.js'
+import { JsHnswVectorIndex } from './hnswIndex.js'
 import {
   DistanceFunction,
   HNSWConfig,
@@ -25,7 +25,7 @@ import { euclideanDistance } from '../utils/index.js'
 import type { BaseStorage } from '../storage/baseStorage.js'
 import { prodLog } from '../utils/logger.js'
 
-// Default HNSW parameters (same as HNSWIndex)
+// Default HNSW parameters (same as JsHnswVectorIndex)
 const DEFAULT_CONFIG: HNSWConfig = {
   M: 16,
   efConstruction: 200,
@@ -58,7 +58,7 @@ export interface TypeAwareHNSWStats {
  */
 export class TypeAwareHNSWIndex {
   // One HNSW index per noun type (lazy initialization)
-  private indexes: Map<NounType, HNSWIndex> = new Map()
+  private indexes: Map<NounType, JsHnswVectorIndex> = new Map()
 
   // Configuration
   private config: HNSWConfig
@@ -105,7 +105,7 @@ export class TypeAwareHNSWIndex {
 
     // Enable COW on each underlying type-specific index
     for (const [type, parentIndex] of parent.indexes.entries()) {
-      const childIndex = new HNSWIndex(this.config, this.distanceFunction, {
+      const childIndex = new JsHnswVectorIndex(this.config, this.distanceFunction, {
         useParallelization: this.useParallelization,
         storage: this.storage || undefined,
         persistMode: this.persistMode
@@ -183,9 +183,9 @@ export class TypeAwareHNSWIndex {
    * Only types with entities get an index.
    *
    * @param type The noun type
-   * @returns HNSWIndex for this type
+   * @returns JsHnswVectorIndex for this type
    */
-  private getIndexForType(type: NounType): HNSWIndex {
+  private getIndexForType(type: NounType): JsHnswVectorIndex {
     // Validate type is a valid NounType
     const typeIndex = TypeUtils.getNounIndex(type)
     if (typeIndex === undefined || typeIndex === null || typeIndex < 0) {
@@ -197,7 +197,7 @@ export class TypeAwareHNSWIndex {
     if (!this.indexes.has(type)) {
       prodLog.info(`Creating HNSW index for type: ${type}`)
 
-      const index = new HNSWIndex(this.config, this.distanceFunction, {
+      const index = new JsHnswVectorIndex(this.config, this.distanceFunction, {
         useParallelization: this.useParallelization,
         storage: this.storage || undefined,
         persistMode: this.persistMode