feat: add universal adapters for browser compatibility

- Create universal adapters for cross-platform support (browser/Node/serverless)
- Replace Node.js-specific imports with universal implementations
- Add OPFS support for browser persistent storage
- Maintain same BrainyData interface across all environments
- Enable real Brainy usage in browser console UI
- Keep package size optimized (no bloat)

Universal adapters in /src/universal/:
- uuid.ts: Cross-platform UUID generation
- crypto.ts: Browser/Node crypto operations
- fs.ts: OPFS/FileSystem/Memory storage adapter
- path.ts: Universal path operations
- events.ts: EventEmitter compatibility layer

This enables 'write once, run anywhere' for Brainy while maintaining
the exact same API. No breaking changes to existing code.

src/brainyData.ts

@@ -3,7 +3,7 @@
  * Main class that provides the vector database functionality
  */
 
-import { v4 as uuidv4 } from 'uuid'
+import { v4 as uuidv4 } from './universal/uuid.js'
 import { HNSWIndex } from './hnsw/hnswIndex.js'
 import {
   HNSWIndexOptimized,
@@ -6071,7 +6071,7 @@ export class BrainyData<T = any> implements BrainyDataInterface<T> {
           // Configure HNSW with disk-based storage when a storage adapter is provided
           const hnswConfig = data.hnswIndex.config || {}
           if (this.storage) {
-            hnswConfig.useDiskBasedIndex = true
+            ;(hnswConfig as any).useDiskBasedIndex = true
           }
 
           this.index = new HNSWIndexOptimized(