Implement a mechanism to register hooks for Capabilities globally within a process, similar to `Agent.instrument_all()`, to improve observability and ease of setup.
### Description One could register a logging hook globally with `Agent.instrument_all()`. There is no such hook for Capabilities, per [this Slack discussion](https://pydanticlogfire.slack.com/archives/C083V7PMHHA/p1775259168280909). Per @DouweM : "I agree it should be easy to set up such a global hook for observability. There isn't currently a way (other than monkey patching / subclassing Agent), but i agree it makes sense for such scenarios. I have a PR open to turn the entire instrumentation feature into a capability, where I can look into generalizing the auto-load aspect as well." ### References https://pydanticlogfire.slack.com/archives/C083V7PMHHA/p1775259168280909