Serve bundled pi-* and TypeBox through an in-process virtual namespace
on Bun 1.3.14+ where `--compile` extras are unreachable via any
filesystem API (issue #3423).
Merge resolution:
- Reconciled `TYPEBOX_SHIM_PATH` with main's #3414 fall-through:
`__resolveTypeBoxShimPath(isCompiled, sourcePath, exists)` returns the
`omp-legacy-pi-bundled:` virtual specifier in compiled mode (no FS
probe) and the on-disk source path otherwise, dropping to null when
the shim file is missing so bare typebox imports fall through to native
resolution.
- Removed the now-dead `--compile` extras path: dropped
`LEGACY_COMPAT_BUILD_ENTRYPOINTS` usage from both build-binary.ts and
ci-release-build-binaries.ts and deleted scripts/binary-entrypoints.ts;
the bundler reaches every surface via legacy-pi-bundled-registry.ts.
- Deleted obsolete tests for the removed bunfs machinery
(legacy-pi-compat-entrypoints, legacy-pi-typebox-shim-validation) and
added regression coverage for __resolveTypeBoxShimPath.
- Dropped the binary-compiling smoke driver per maintainer request.
Verified: bun check clean; 77 extensibility tests pass; instrumented
compiled-binary run confirmed onLoad fires for all bundled specifiers.