fix(demo): WASM loading broken on entity-RAG and SIMD benchmark pages

- Add missing storage.js snippet (edgevec-59b9f14da3349a9d) that was
  blocked by docs/demo/pkg/.gitignore — caused 404 on GitHub Pages,
  breaking entity-RAG demo on all platforms including iOS
- Fix SIMD benchmark import path from ../../pkg/ to ./pkg/

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: matte1782

docs/demo/pkg/snippets/edgevec-59b9f14da3349a9d/src/js/storage.js

@@ -0,0 +1,46 @@
+export class IndexedDbBackend {
+    static async write(name, data) {
+        return new Promise((resolve, reject) => {
+            const req = indexedDB.open("EdgeVecDB", 1);
+            req.onupgradeneeded = (e) => {
+                const db = e.target.result;
+                if (!db.objectStoreNames.contains('files')) {
+                    db.createObjectStore('files');
+                }
+            };
+            req.onsuccess = (e) => {
+                const db = e.target.result;
+                const tx = db.transaction(['files'], 'readwrite');
+                const store = tx.objectStore('files');
+                store.put(data, name);
+                tx.oncomplete = () => {
+                    resolve();
+                };
+                tx.onerror = () => reject(tx.error);
+            };
+            req.onerror = () => reject(req.error);
+        });
+    }
+
+    static async read(name) {
+        return new Promise((resolve, reject) => {
+            const req = indexedDB.open("EdgeVecDB", 1);
+            req.onsuccess = (e) => {
+                const db = e.target.result;
+                const tx = db.transaction(['files'], 'readonly');
+                const store = tx.objectStore('files');
+                const getReq = store.get(name);
+                getReq.onsuccess = () => {
+                    if (getReq.result) {
+                        resolve(getReq.result);
+                    } else {
+                        reject(new Error(`File ${name} not found`));
+                    }
+                };
+                getReq.onerror = () => reject(getReq.error);
+            };
+            req.onerror = () => reject(req.error);
+        });
+    }
+}
+

docs/demo/simd_benchmark.html

@@ -1106,7 +1106,7 @@ <h2 class="section__title">BROWSER_COMPATIBILITY</h2>
       try {
         log('Initializing EdgeVec WASM module...', 'info');
 
-        const { default: init, EdgeVec, EdgeVecConfig } = await import('../../pkg/edgevec.js');
+        const { default: init, EdgeVec, EdgeVecConfig } = await import('./pkg/edgevec.js');
         await init();
 
         state.edgevec = { EdgeVec, EdgeVecConfig };