compile: dynamic import() namespace of a pure re-export chunk is empty (breaks esbuild --splitting shared chunks)

[proggeramlug]

Summary

The namespace object for a dynamically-imported pure re-export chunk is empty. This is the canonical shape esbuild/bun emit for a shared chunk under --splitting, so it breaks code-split bundles.

Repro

esbuild src/index.ts --bundle --splitting --format=esm --outdir=out --platform=node
perry out/index.js -o app && ./app

esbuild emits out/agent-VP4LHHJR.js as a 2-statement re-export file:

import { run } from "./chunk-XXXX.js";
export { run };

Result:

	node	perry main
typeof ns	object	object
typeof ns.run	function	undefined
ns.run()	"[shared-util] agent"	(missing)
a chunk containing real code (not a re-export)	works	works

Perry ingests the whole graph correctly (Found 4 module(s): 4 native, 0 JavaScript) — the chunk-set ingestion from #5572 works. It is specifically the re-export-only chunk whose namespace comes out empty.

Worse: an unguarded ns.run() printed undefined rather than throwing ns.run is not a function, so this is a silent wrong answer.

Likely the same family as #5916 (barrel re-export of a namespace value never gets a wrapper).

Split out of #5207, whose headline ask (ingest a bundler's chunk-set) did ship.