hermes - 💡(How to fix) Fix [Bug]: WebUI: assistant colon-ended streaming messages lost when switching session pages [1 pull requests]

Describe the bug

In the Hermes WebUI, when the agent is in the middle of streaming a multi-round task chain, assistant text messages that end with a colon (:) — the intermediate reasoning / "I'll do X next" type commentary — are lost after switching away from the session page and back.

Tool-call (function call) blocks are preserved correctly; only the streaming assistant text messages that precede them disappear from the transcript.

What is preserved:

• Tool-call messages (function call blocks) ✅
• Final assistant responses ✅

What is lost:

• Streamed assistant text messages that end with ":" — the intermediate commentary during a task chain ❌

Steps to reproduce:

1. Start a session in the Hermes WebUI
2. Give the agent a multi-step task (e.g., "search the web, read a file, then write a summary")
3. Observe the streaming task chain — the agent outputs messages like "Let me search for that:" or "Reading the file:" as intermediate steps before making tool calls
4. While the agent is still streaming, click on another session in the sidebar to switch pages
5. Click back to the original session
6. The tool-call blocks are still there, but the colon-ended assistant text messages that preceded them are missing from the transcript

Expected behavior: Colon-ended streamed messages should be persisted to the session transcript just like final responses, so they remain visible when the user returns to the session.

Actual behavior: The intermediate streaming text messages are silently dropped from the session state when navigating away mid-stream.

Environment:

• Hermes WebUI (api_server adapter)
• Browser: any
• Model/provider: any with streaming

Additional context: This significantly impacts the WebUI experience for complex multi-step tasks where users rely on seeing the agent's reasoning flow between tool calls. The CLI/terminal session does not have this issue because the output stream is continuous.