fix: rewrite compiler-runtime chunk to use importShared in remote builds

[pedrotainha]

Summary

• Detect react/compiler-runtime chunks in generateBundle (remote builds only)
• Rewrite them to obtain React via importShared("react") instead of a direct bundled import
• Includes helpers: findImportSharedExportName (handles minified exports) and computeRelativePath

Problem

When a remote app uses React Compiler (babel-plugin-react-compiler), Rollup bundles react/compiler-runtime as a separate chunk that imports React directly:

import{r as R}from"./index-XYZ.js";  // direct React import, NOT importShared

The AST transform in remote-production.ts only matches exact shared module names (react), not sub-exports (react/compiler-runtime). The result: the compiler-runtime chunk gets its own React instance, separate from the host's shared one.

At render time, the shared React has its hooks dispatcher initialized (H), but the isolated copy has H = null → crash:

TypeError: Cannot read properties of null (reading 'useMemoCache')

Fix

In generateBundle, after all chunks are built:

1. Find the __federation_fn_import chunk and discover the exported name for importShared (handles both minified and unminified forms)
2. Find compiler-runtime chunks that access __CLIENT_INTERNALS_DO_NOT_USE_OR_WARN_USERS_THEY_CANNOT_UPGRADE
3. Rewrite them to use importShared("react") via top-level await

Only applies to remote builds (builderInfo.isRemote) — the host owns the React instance directly and doesn't need the patch.

Test plan

• Build a remote with babel-plugin-react-compiler enabled
• Verify compiler-runtime-*.js chunk uses importShared instead of direct import
• Load remote in host — verify useMemoCache works without crash
• Verify host build is NOT affected (no patch applied)

Fixes #742