[ZEPPELIN-6674] Prove Shared Notebook Core port identity

[voidmatcha]

What is this PR for?

Prove that separately built Angular host and React remote code receive the exact same host-owned NotebookCorePort object. The build also rejects a React remote that bundles its own Shared Notebook Core runtime.

What type of PR is it?

Improvement

Todos

• Add the Angular host and React remote proof
• Reject duplicate Core runtime bundles
• Add the proof to the frontend build

What is the Jira issue?

ZEPPELIN-6674

How should this be tested?

cd zeppelin-web-angular
npm run typecheck:notebook-core
npm run build:notebook-core-port-proof
npm run test:notebook-core-port-identity

Screenshots (if appropriate)

Not applicable.

Questions:

• Does the license files need to update? No
• Is there breaking changes for older versions? No
• Does this needs documentation? No

[voidmatcha]

Some context the description leaves out:

Why this PR is needed. This is part of ZEPPELIN-6627 and the second child of ZEPPELIN-6669, after ZEPPELIN-6670 (#5469) and before ZEPPELIN-6675. The React remote has no Module Federation shared scope, so a stateful Core imported by both the host and the remote would be two separate module instances. ZEPPELIN-6669 therefore makes the Angular host the single owner: it creates the port once and passes it to the remote through mount props. This PR proves that the remote receives that exact object across separate builds.

Where the runtime-bundle rejection applies. The webpack plugin that fails a build bundling @zeppelin/notebook-core is used only by the proof remote under e2e/core-contract/react-remote/, not by projects/zeppelin-react. For production React code, the import-boundary check now rejects runtime imports of the Core package. That goes slightly beyond ZEPPELIN-6674, which asks for it on the proof remote, and follows the single-owner rule in ZEPPELIN-6669.