OpenRouter reasoning renders incorrectly in Agent Swarm TUI

[nicko-ai]

Agent Swarm CLI can render OpenRouter reasoning incorrectly in the TUI.

Observed with Claude Haiku 4.5 through OpenRouter:

• reasoning text could duplicate or overlap while streaming
• assistant text could appear before the reasoning block finished
• the UI did not preserve the upstream-style Thinking spinner and Thought: <elapsed> transition

Expected behavior:

• show Thinking while reasoning streams
• show Thought: <elapsed> after reasoning completes
• keep one coherent reasoning block followed by one assistant answer