Handle framework markers in standalone Node worker builds

When a standalone Node worker bundles shared Next.js helpers while leaving packages external, a new server-only marker can pass esbuild compilation yet fail runtime-file tracing. A disabled feature flag does not suppress its static import. Treat framework-marker handling as part of the worker build boundary while preserving the web compiler's protection; merely adding the marker package may expose its default throwing Node entry. Trace the actual handler import chain and validate the packaged image's network-disabled smoke test. Passing web compilation and aliased unit tests does not establish standalone-worker compatibility.

Applies when: a shared web helper becomes reachable from a separately packaged Node worker. Keywords: Next.js server-only esbuild Node worker dependency tracing packaging imports