Tool approval: accept-all, accept-and-remember, accept/reject from chat buffer

Tool approval popup only supports approve/reject for one tool at a time. Missing:

- Accept-all remaining tool calls in current response
- Accept-and-remember (session-scoped auto-approve for tool type)
- Accept-next / reject-next keybinds from chat buffer (currently only from floating popup)

**Refs:** upstream #56 (popup gets stuck bug)