feat: implement chunked storage for IndexedDB to optimize memory usage

- Replace single-file storage with chunk-based architecture
- Add FileMetadata store for tracking file information
- Implement DataChunks store with composite key [filename, chunkIndex]
- Update write operations to append only to relevant chunks
- Maintain backward compatibility with existing API
- Improve performance for 500Hz continuous data streams
- Reduce memory usage from O(n) to O(1) for append operations

BREAKING CHANGE: Database version upgraded to 3. Existing data will be migrated automatically.

Author: Amanmahe

src/app/npg-lite/page.tsx

@@ -1859,7 +1859,7 @@ const NPG_Ble = () => {
                                             <p className="text-sm">
                                                 Update firmware using <a
                                                     className="font-semibold text-blue-600 hover:underline"
-                                                    href="https://github.com/upsidedownlabs/NPG-Lite-Arduino-Firmware"
+                                                    href="https://upsidedownlabs.github.io/NPG-Lite-Flasher-Web"
                                                     target="_blank"
                                                     rel="noopener noreferrer"
                                                 >