feat: replace hnswlib-node with hnswlib-wasm for cross-platform compatibility

Remove native C++ dependency (hnswlib-node) that requires Visual Studio Build Tools
on Windows. Replace with hnswlib-wasm which runs everywhere via WebAssembly.

Based on the author's own wasm implementation from commit d5581bb, adapted for
the current v2.11.3 dual-index architecture.

Changes:
- Replace hnswlib-node ^3.0.0 with hnswlib-wasm ^0.8.2
- Use lazy async import for hnswlib-wasm module
- Adapt to wasm API: 3-arg constructor, sync read/writeIndex, Float32Array params
- Remove vectorToArray() helper (wasm accepts Float32Array directly)

Author: kui123456789

package.json

@@ -36,7 +36,7 @@
     "@opencode-ai/plugin": "^1.0.162",
     "@xenova/transformers": "^2.17.2",
     "franc-min": "^6.2.0",
-    "hnswlib-node": "^3.0.0",
+    "hnswlib-wasm": "^0.8.2",
     "iso-639-3": "^3.0.1"
   },
   "devDependencies": {

src/services/sqlite/hnsw-index.ts

@@ -9,15 +9,24 @@ import {
 import { join, dirname, basename } from "node:path";
 import { log } from "../logger.js";
 import { CONFIG } from "../../config.js";
-import { HierarchicalNSW } from "hnswlib-node";
+
+let HNSWLib: any = null;
+
+async function loadHNSWLib(): Promise<any> {
+  if (!HNSWLib) {
+    const module = await import("hnswlib-wasm");
+    HNSWLib = module;
+  }
+  return HNSWLib;
+}
 
 export interface HNSWIndexData {
   id: string;
   vector: Float32Array;
 }
 
 export class HNSWIndex {
-  private index: HierarchicalNSW | null = null;
+  private index: any = null;
   private idMap: Map<number, string> = new Map();
   private reverseMap: Map<string, number> = new Map();
   private nextId: number = 0;
@@ -34,15 +43,17 @@ export class HNSWIndex {
   private async ensureInitialized(): Promise<void> {
     if (this.initialized) return;
 
+    const hnsw = await loadHNSWLib();
+
     const dir = dirname(this.indexPath);
     if (!existsSync(dir)) {
       mkdirSync(dir, { recursive: true });
     }
 
     if (existsSync(this.indexPath)) {
       try {
-        this.index = new HierarchicalNSW("cosine", this.dimensions);
-        await this.index.readIndex(this.indexPath);
+        this.index = new hnsw.HierarchicalNSW("cosine", this.dimensions);
+        this.index.readIndex(this.indexPath);
 
         const metaPath = this.indexPath + ".meta";
         if (existsSync(metaPath)) {
@@ -60,22 +71,16 @@ export class HNSWIndex {
           path: this.indexPath,
           error: String(error),
         });
-        this.index = new HierarchicalNSW("cosine", this.dimensions);
-        await this.index.initIndex(this.maxElements);
+        this.index = new hnsw.HierarchicalNSW("cosine", this.dimensions, this.maxElements);
       }
     } else {
-      this.index = new HierarchicalNSW("cosine", this.dimensions);
-      await this.index.initIndex(this.maxElements);
+      this.index = new hnsw.HierarchicalNSW("cosine", this.dimensions, this.maxElements);
       log("HNSW index created", { path: this.indexPath, dimensions: this.dimensions });
     }
 
     this.initialized = true;
   }
 
-  private vectorToArray(vector: Float32Array): number[] {
-    return Array.from(vector);
-  }
-
   async insert(id: string, vector: Float32Array): Promise<void> {
     await this.ensureInitialized();
 
@@ -85,7 +90,7 @@ export class HNSWIndex {
     }
 
     const internalId = this.nextId++;
-    await this.index!.addPoint(this.vectorToArray(vector), internalId);
+    this.index!.addPoint(vector, internalId);
     this.idMap.set(internalId, id);
     this.reverseMap.set(id, internalId);
 
@@ -102,7 +107,7 @@ export class HNSWIndex {
       }
 
       const internalId = this.nextId++;
-      await this.index!.addPoint(this.vectorToArray(item.vector), internalId);
+      this.index!.addPoint(item.vector, internalId);
       this.idMap.set(internalId, item.id);
       this.reverseMap.set(item.id, internalId);
     }
@@ -114,7 +119,7 @@ export class HNSWIndex {
     await this.ensureInitialized();
 
     try {
-      const results = await this.index!.searchKnn(this.vectorToArray(queryVector), k);
+      const results = this.index!.searchKnn(queryVector, k);
 
       return results.neighbors
         .map((internalId: number, idx: number) => ({
@@ -148,7 +153,7 @@ export class HNSWIndex {
       mkdirSync(dir, { recursive: true });
     }
 
-    await this.index.writeIndex(this.indexPath);
+    this.index.writeIndex(this.indexPath);
 
     const metaPath = this.indexPath + ".meta";
     const meta = {