runtime-core: loadShare fails after dynamic registerShared()

[dmchoi77]

Describe the bug

ModuleFederation.registerShared() registers a shared provider in shareScopeMap, but does not update instance.options.shared.

This leaves the runtime in an inconsistent state: the provider exists in shareScopeMap, but the shared configuration is missing from instance.options.shared.

When loadShare() is called after dynamic registration, it cannot reliably resolve the newly registered shared module and may throw:

targetShared.get is not a function

The issue can be reproduced with @module-federation/runtime-core@2.8.1 using the reproduction repository below.

I intend to submit a fix for this issue in PR #4950.

Reproduction

https://github.com/dmchoi77/runtime-core-register-shared-repro

Used Package Manager

pnpm

System Info

OS: macOS
Node.js: v22.22.0
pnpm: 10.28.0
Package: @module-federation/runtime-core@2.8.1

Validations

• Read the docs.
• Read the common issues list.
• Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
• Make sure this is a Module federation issue and not a framework-specific issue.
• The provided reproduction is a minimal reproducible example of the bug.