``Nanobot.run()`` has always documented ``RunResult.tools_used`` and
``RunResult.messages`` but actually returned ``[]`` for both, so SDK
consumers could never inspect which tools fired or what the final
message list looked like — the only useful field was ``content``.
This threads the data out via a tiny ``_SDKCaptureHook`` that installs
alongside any user-supplied hooks. The capture hook accumulates tool
names across iterations and snapshots the message list on each
``after_iteration`` call; the last snapshot reflects end-of-turn state.
Only the SDK facade is touched: ``AgentLoop.process_direct`` and
``AgentRunner`` signatures are unchanged, so channels / CLI / API paths
are unaffected.
