[Bug] Inconsistent Output & Unhandled Pipeline Errors

[Smilin01]

Problem

The RAG pipeline fails silently in several edge cases, returning empty or malformed responses
with no user-facing error message.

Known Failure Scenarios

• Jina Reader returns empty/blocked content → pipeline hangs
• All SearXNG instances fail + DuckDuckGo Lite also fails → blank answer
• LLM outputs malformed citation markers → broken [1] references in UI
• SSE stream closes unexpectedly → UI stuck in loading state

Expected Behavior

• Each pipeline stage should have a typed error boundary
• User sees a clear, actionable message when search/extraction fails
• Citations should be validated before rendering
• SSE timeout should trigger a graceful UI reset

Suggested Approach

• Wrap each stage (search → scrape → chunk → synthesize) in try/catch with typed errors
• Add a PipelineError type with stage + reason fields
• UI: show partial results + error banner instead of blank screen

Labels

bug reliability help wanted