run_agent.py passes httpx.Timeout(connect=30, read=120, write=1800,
pool=30) as the timeout kwarg on the streaming path. The OpenAI SDK
handles this natively, but CopilotACPClient._create_chat_completion()
called float(timeout or default), which raises TypeError because
httpx.Timeout doesn't implement __float__.
Normalize the timeout before passing to _run_prompt: plain floats/ints
pass through, httpx.Timeout objects get their largest component
extracted (write=1800s is the correct wall-clock budget for the ACP
subprocess), and None falls back to the 900s default.
25c7b1baa7