The 1.0s sleep between sequential tool calls has been present since the
initial commit with no documented rationale. It sleeps between local
tool executions — the next LLM request goes out only after the whole
batch — so it rate-limits nothing, and the parallel read-only path
already runs with no delay. Every multi-tool turn pays (N-1) seconds
of dead time. Remove the sleep, the internal tool_delay plumbing, and
dead test assignments. AIAgent.__init__ keeps tool_delay as a
deprecated no-op keyword for one release so existing programmatic
callers construct cleanly; passing it emits a DeprecationWarning.
