Update sqlite vec android

Author: ospfranco

android/src/main/libsqlitevec/arm64-v8a/libsqlite_vec.so

@@ -51,7 +51,7 @@
     "fts5": true,
     "rtree": true,
     "crsqlite": false,
-    "sqliteVec": false,
+    "sqliteVec": true,
     "performanceMode": true,
     "tokenizers": [
       "wordtokenizer",

android/src/main/libsqlitevec/armeabi-v7a/libsqlite_vec.so

@@ -775,4 +775,46 @@ describe('Queries tests', () => {
     const res = db.executeSync('PRAGMA user_version');
     expect(res.rows).toDeepEqual([{user_version: 0}]);
   });
+
+  it('sqlite-vec extension: vector similarity search', async () => {
+    // Create a virtual table for storing vectors
+    await db.execute(`
+      CREATE VIRTUAL TABLE vec_items USING vec0(
+        embedding FLOAT[8]
+      )
+    `);
+
+    // Insert some sample vectors
+    await db.execute(`
+      INSERT INTO vec_items(rowid, embedding)
+      VALUES
+        (1, '[-0.200, 0.250, 0.341, -0.211, 0.645, 0.935, -0.316, -0.924]'),
+        (2, '[0.443, -0.501, 0.355, -0.771, 0.707, -0.708, -0.185, 0.362]'),
+        (3, '[0.716, -0.927, 0.134, 0.052, -0.669, 0.793, -0.634, -0.162]'),
+        (4, '[-0.710, 0.330, 0.656, 0.041, -0.990, 0.726, 0.385, -0.958]')
+    `);
+
+    // Perform KNN query to find the 2 nearest neighbors
+    const queryVector = '[0.890, 0.544, 0.825, 0.961, 0.358, 0.0196, 0.521, 0.175]';
+    const result = await db.execute(`
+      SELECT rowid, distance
+      FROM vec_items
+      WHERE embedding MATCH ?
+      ORDER BY distance
+      LIMIT 2
+    `, [queryVector]);
+
+    // Verify results
+    expect(result.rows.length).toEqual(2);
+    expect(result.rows[0]!.rowid).toEqual(2);
+    expect(result.rows[1]!.rowid).toEqual(1);
+    
+    // Verify distances are positive numbers
+    const distance0 = result.rows[0]!.distance as number;
+    const distance1 = result.rows[1]!.distance as number;
+    expect(typeof distance0).toEqual('number');
+    expect(distance0 > 0).toBeTruthy();
+    expect(distance1 > 0).toBeTruthy();
+  });
+  
 });