Compiled builds crash on first prompt: undefined layer node from filesystem search import cycle

Description

Compiled builds of the server crash on the first prompt while booting a location:

TypeError: undefined is not an object (evaluating 'node.name')

The same code works when run from source (bun run).

Cause: packages/core/src/filesystem/search.ts imports the FileSystem self-namespace from ../filesystem to use Entry.make / Match.make (values re-exported from @opencode-ai/schema/filesystem). That creates a runtime import cycle between filesystem.ts and filesystem/search.ts. In bundled output the cycle can leave FileSystemSearch.node undefined when filesystem.ts builds its layer node, so the layer graph walker dereferences an undefined node.

This blocks any self-contained/compiled distribution of the kernel (for example embedding it as a headless engine behind a native desktop shell).

Reproduction

1. Build a standalone binary (bun run --cwd packages/opencode script/build.ts --single).
2. Run serve, create a session, send prompt_async.
3. The session errors with the TypeError above and the assistant message never completes.

Expected

The compiled binary behaves like the source build: the prompt runs and the assistant message completes.

Start with packages/core/src/filesystem/search.ts and packages/core/src/filesystem.ts, then reproduce the failure with bun run --cwd packages/opencode script/build.ts --single and the serve/prompt_async sequence. Trace the runtime cycle involving FileSystem, Entry.make, and Match.make. Done means the compiled binary completes the prompt like the source build without the undefined node error.