Replaced setTimeout hacks with proper polling mechanism:
- Added pollForQueryResponse() function with configurable polling interval
- Polls every 500ms with 30s timeout
- Properly handles DELIVERED and FAILED message states
- Throws errors for failures and timeouts
Updated dashboard to use polling instead of arbitrary delays:
- Removed setTimeout(resolve, 1000) hacks
- Added proper async/await for query responses
- Improved response data parsing for new query format
- Better error handling via polling exceptions
This fixes race conditions and unreliable data loading.
Fixes#298
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
