feat(native): add prebuilt Node-API flock support

packages/experimental/webworker-runtime/src/node/builtins.ts

@@ -45,7 +45,7 @@ import * as nodeNet from './builtin_modules/mock/net.ts'
 import * as nodeSqlite from './builtin_modules/mock/sqlite.ts'
 import * as nodeVm from './builtin_modules/mock/vm.ts'
 import * as nodeWorkerThreads from './builtin_modules/mock/worker_threads.ts'
-import * as fsExt from './external_packages/fs-ext.ts'
+import * as systemFlock from './external_packages/node-addon-system-flock.ts'
 import * as koffi from './external_packages/koffi.ts'
 import * as nodePty from './external_packages/node-pty.ts'
 import * as piAi from './external_packages/pi-ai.ts'
@@ -84,9 +84,9 @@ const BUILTINS: Record<string, StaticModuleFactory> = {
   zlib: () => nodeZlib,
 }
 
-/** External npm packages replaced wholesale (structural not-implemented stubs and fakes). */
+/** Exact package or subpath specifiers served by worker stubs and fakes. */
 const EXTERNALS: Record<string, StaticModuleFactory> = {
-  'fs-ext': () => fsExt,
+  '@deepseek-ai/node-addon-system/flock': () => systemFlock,
   'koffi': () => koffi,
   'sharp': () => sharp,
   'node-pty': () => nodePty,

packages/experimental/webworker-runtime/src/node/external_packages/fs-ext.ts

@@ -1,42 +0,0 @@
-/**
- * `fs-ext` stub: the kernel file-lock bridge the JSONL session backend uses
- * for cross-process write exclusion. The worker is a single-process
- * deployment whose in-process write claim already excludes every writer, so
- * both flock faces succeed immediately; every other entry is loud because
- * nothing in the worker reaches it.
- */
-import { notImplementedFail } from '../notImplementedFail.ts'
-
-const MODULE = 'fs-ext'
-
-/**
- * Asynchronous flock face; the single-process worker grants every lock.
- * @param _fd - file descriptor (unused).
- * @param _flags - lock flags (unused).
- * @param callback - completion callback, invoked with no error.
- */
-export function flock(_fd: number, _flags: unknown, callback: (error: null) => void): void {
-  queueMicrotask(() => { callback(null) })
-}
-
-/**
- * Synchronous flock face; the single-process worker grants every lock.
- */
-export function flockSync(): void {}
-
-/** Unreached in the worker; loud refusal. */
-export const fcntl = notImplementedFail(MODULE, 'fcntl')
-/** Unreached in the worker; loud refusal. */
-export const fcntlSync = notImplementedFail(MODULE, 'fcntlSync')
-/** Unreached in the worker; loud refusal. */
-export const seek = notImplementedFail(MODULE, 'seek')
-/** Unreached in the worker; loud refusal. */
-export const seekSync = notImplementedFail(MODULE, 'seekSync')
-/** Unreached in the worker; loud refusal. */
-export const statVFS = notImplementedFail(MODULE, 'statVFS')
-
-/** CommonJS interop marker: the worker loader hands `default` to default imports (see ./builtins.ts). */
-export const __esModule = true
-
-/** The fs-ext face its consumers read. */
-export default { flock, flockSync, fcntl, fcntlSync, seek, seekSync, statVFS }

packages/experimental/webworker-runtime/src/node/external_packages/node-addon-system-flock.ts

@@ -0,0 +1,20 @@
+/**
+ * Single-process worker replacement for `@deepseek-ai/node-addon-system/flock`.
+ * The JSONL backend's in-process write claim already excludes every writer,
+ * so its kernel-lock request succeeds without acquiring another resource.
+ */
+
+/**
+ * Grant the single-process worker's exclusive-lock request immediately.
+ * @param _fd - file descriptor (unused).
+ * @returns an already-fulfilled promise.
+ */
+export function tryLockExclusive(_fd: number): Promise<void> {
+  return Promise.resolve()
+}
+
+/** CommonJS interop marker for the worker module loader. */
+export const __esModule = true
+
+/** The native flock API used by the JSONL backend. */
+export default { tryLockExclusive }

packages/experimental/webworker-runtime/src/node/external_packages/replaced-externals.ts

@@ -1,16 +1,15 @@
 /**
- * Names of external npm packages the worker replaces wholesale. Kept in a module
- * with no imports so both consumers can read it: the runtime builtin table
- * (`./builtins.ts`) and the build-time VFS image collector, which must leave
- * these packages out of the image entirely — the loader answers them from the
- * bundle before it ever reaches `node_modules`.
+ * Exact package or subpath specifiers served from the worker bundle. Kept
+ * import-free for the runtime builtin table and the VFS image collector.
+ * Whole-package entries are omitted from the image; subpath entries leave
+ * their parent package available to other consumers.
  */
 
-/** External packages served from the worker bundle instead of the VFS. */
+/** Package or subpath specifiers served from the worker bundle instead of the VFS. */
 export const REPLACED_EXTERNAL_PACKAGES: readonly string[] = [
   '@earendil-works/pi-ai',
   '@vscode/ripgrep',
-  'fs-ext',
+  '@deepseek-ai/node-addon-system/flock',
   'koffi',
   'node-pty',
   'sharp',