Webhooks enhancements

### Problem Statement

My webhooks formation is different from sentry webhooks formation.
I can't inegtrate my webhooks.

### Solution Brainstorm

I think sentry webhooks plugin should add a feature, "custom script".
Users can write custom script to transform data.
The input parameter is origin sentry webhooks data, and output data is user transformed data.
Thank you\~

We want to define a set of [lightweight metrics]() that SDKs can automatically collect for e.g. framework, language or platform, focusing only on signals that **do NOT overlap with Tracing**. Ideally these metrics should give a quick sense of app or runtime health, … while deeper investigation will still rely on traces or profiles.

Examples**:**

* Node.js runtime metrics (e.g., event loop delay, heap usage)
* Prisma-related metrics in Next.js
* Mobile CPU / memory usage to help surface potential ANRs or app hangs

---

**Candidate Metrics (add more below)**

* …

*(please also add ideas, questions or examples in comments)*