[WIP] Investigate issues with ingestion page launch

[Copilot]

Investigation Plan: Ingestion Page Launch Issues

Completed Investigation

• Explored repository structure and documentation
• Located ingestion page component (frontend/src/pages/Ingestion.tsx)
• Identified ingestion page is lazy-loaded in App.tsx
• Started frontend dev server successfully
• Attempted to access ingestion page in browser
• Identified authentication requirement (redirects to login)
• Bypassed auth to view ingestion page
• Captured screenshot of ingestion page
• Analyzed console errors and network failures
• Created comprehensive diagnosis document

Issues Fixed

• ✅ Added error handling for backend API failures
• ✅ Implemented retry logic with exponential backoff for subjects query
• ✅ Added graceful degradation - manual subject ID entry when backend unavailable
• ✅ Added error states for preview and validation steps
• ✅ Improved user feedback with warning alerts
• ✅ Page now loads successfully even when backend is down

Remaining Tasks

• Document backend setup for developers
• Add backend dependency fixes (aiosqlite, etc.)
• Test full ingestion workflow with backend running
• Create automated tests for error scenarios

Original prompt

Diagnose and investigate issues with ingestion page launch

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✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[teoat]

retry again, also take screenshot of completed page

[teoat]

Complete remaining tasks