Changes
PR #2029 by ksylvan: Web UI: Fix streaming chat: tokens now accumulate in order into a single message
- Feat: improve streaming message handling and SSE buffer parsing
- Append content to existing assistant messages instead of replacing, and fix loading message removal to search by index rather than position
- Refactor SSE buffer splitting to always retain incomplete segments, and trim segments before parsing to handle whitespace edge cases
- Consolidate duplicate message update logic across chat components and process remaining buffer after stream completion more reliably