Changes
PR #1940 by ksylvan: Rewrite Ollama chat handler to support proper streaming responses
- Refactor Ollama chat handler to support proper streaming responses with real-time SSE data parsing
- Replace single-read body parsing with streaming bufio.Scanner approach and implement writeOllamaResponse helper function
- Add comprehensive error handling improvements including proper HTTP error responses instead of log.Fatal to prevent server crashes
- Fix upstream error handling to return stringified error payloads and validate Fabric chat URL hosts
- Implement proper request context propagation and align duration fields to int64 nanosecond precision for consistency