0.166.0

• Fix resuming a chat restoring the default agent instead of the chat's own agent when it was picked before the first message. #657
• Fix the "dropped N history entries from a previous provider" note repeating on every prompt after a model swap; it now shows once per swap. #660
• Fix install script exiting silently when unzip is missing; report missing tools and download errors clearly, and keep the existing binary on failure. #655
• Fix context-overflow auto-recovery not triggering for llama.cpp's llama-server, whose "exceeds the available context size" error went unrecognized.
• Speed up rollback, flags and forks on long chats via the incrementalUpdates capability: chat/truncated, positioned flags, and paged /fork, /btw and chat/fork.
• grep no longer reports no matches as a failed tool call; backend errors still fail with the backend message.