84950fa371
This change introduces parallel chunked downloading for large model files (.mjb) directly into WASM linear memory, enables model loading without full page reloads and reduces memory overhead. Key changes: - Implement a chunked model endpoint in the Python web server to support range requests. - Add parallel chunked fetching in the frontend with retry logic and a single-fetch fallback. - Increase initial WASM memory to 3 GB to accommodate large models and prevent heap fragmentation. - Support in-place model reloading in the C++ client, including texture cache invalidation when the Filament context is recreated. - Display a model download progress bar and model parsing/loading banner to the UI. - Fixes model drag and drop (caused by typo in sessionId, corrected to session_id). PiperOrigin-RevId: 960249236 Change-Id: Icac89e6a4ca099882aaf9b111744c1b6ab0cc6c1