[STAL-1960] Implement ddsa Violation bridge

[jasonforal]

What problem are you trying to solve?

JavaScript rules need to report violations back to the Rust static-analysis-kernel.

What is your solution?

This PR is small, and implements the bridge that will be used to pass Violation objects from JavaScript to Rust. We do this by passing them indirectly through a pre-allocated global v8::Array:

Flow

1. ddsa runtime exposes a v8::Array, attached to globalThis (for now, let's call it "ddsa_violations"). This array is empty.
2. JavaScript creates a Violation class instance: const violation = ddsa.Violation.new(/* ... */);
3. JavaScript calls globalThis.ddsa_violations.push(violation); This mutates the global v8::Array.
4. JavaScript rule execution ends with no return value (i.e. "undefined" return, according to v8).
5. On the Rust side, the v8::Array is drained: each v8::Object (Violation) that was pushed by JavaScript is removed from the array and converted to a js::Violation<Instance> struct.

Alternatives considered

The JavaScript script could return a value.

• While this would work, I passed on it because we use a "bridge" abstraction everywhere else to pass values and wanted to keep it consistent.

What the reviewer should know

• This is not currently hooked up to anything. A future PR will integrate this as the final step in a rule's execution.