refactor(util): extract the shared no-shell native-command runner to dsh-native-command

master's toolcall-open extracted runNativeCommand inside apiproxy for the
openPath opener while the picker seam had moved the native chooser (its other
consumer) into directory-picker-native; after the merge the two packages each
carried a verbatim copy. The runner now lives in packages/util/native-command
(zero-dependency library, per the util-group contract) and both native
integrations depend on it.

packages/host/apiproxy/package.json

@@ -45,6 +45,7 @@
     "@deepseek-ai/dsh-commands": "workspace:^",
     "@deepseek-ai/dsh-host-directory-picker": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
+    "@deepseek-ai/dsh-native-command": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-persistence": "workspace:^",
     "@deepseek-ai/dsh-session-projection": "workspace:^",

packages/host/apiproxy/src/native-command.ts

@@ -1,38 +0,0 @@
-/** Shared no-shell `execFile` runner for native host dialogs and openers. */
-
-import { execFile } from 'node:child_process'
-
-/** Testable command boundary; native implementations never invoke a shell. */
-export type NativeCommandRunner = (
-  command: string,
-  args: readonly string[],
-  signal: AbortSignal,
-) => Promise<{ stdout: string; stderr: string }>
-
-/**
- * Run a host command with utf8 stdio, abort propagation, and Windows hide.
- * @param command - executable path or PATH name.
- * @param args - argv (never a shell string).
- * @param signal - caller/connection lifetime; abort terminates the child.
- * @returns captured stdout/stderr on exit 0.
- */
-export const runNativeCommand: NativeCommandRunner = (command, args, signal) =>
-  new Promise((resolve, reject) => {
-    execFile(
-      command,
-      [...args],
-      { encoding: 'utf8', signal, windowsHide: true },
-      (error, stdout, stderr) => {
-        if (error !== null) {
-          const failure = Object.assign(new Error(error.message, { cause: error }), {
-            code: error.code,
-            stdout,
-            stderr,
-          })
-          reject(failure)
-          return
-        }
-        resolve({ stdout, stderr })
-      },
-    )
-  })

packages/host/apiproxy/src/native-path-opener.ts

@@ -1,6 +1,6 @@
 /** Cross-platform open-with-default-application used by the local GUI carrier. */
 
-import { runNativeCommand, type NativeCommandRunner } from './native-command.ts'
+import { runNativeCommand, type NativeCommandRunner } from '@deepseek-ai/dsh-native-command'
 
 /** Testable command boundary; native implementations never invoke a shell. */
 export type PathOpenerRunner = NativeCommandRunner

packages/host/apiproxy/tsconfig.json

@@ -55,6 +55,9 @@
     },
     {
       "path": "../../support/invariants"
+    },
+    {
+      "path": "../../util/native-command"
     }
   ]
 }

packages/host/directory-picker-native/package.json

@@ -27,7 +27,8 @@
   ],
   "license": "BSD-3-Clause",
   "dependencies": {
-    "@deepseek-ai/dsh-host-directory-picker": "workspace:^"
+    "@deepseek-ai/dsh-host-directory-picker": "workspace:^",
+    "@deepseek-ai/dsh-native-command": "workspace:^"
   },
   "peerDependencies": {
     "@deepseek-ai/dsh-invariants": "^0.0.1",

packages/host/directory-picker-native/src/native-command.ts

@@ -1,38 +0,0 @@
-/** Shared no-shell `execFile` runner for native host dialogs and openers. */
-
-import { execFile } from 'node:child_process'
-
-/** Testable command boundary; native implementations never invoke a shell. */
-export type NativeCommandRunner = (
-  command: string,
-  args: readonly string[],
-  signal: AbortSignal,
-) => Promise<{ stdout: string; stderr: string }>
-
-/**
- * Run a host command with utf8 stdio, abort propagation, and Windows hide.
- * @param command - executable path or PATH name.
- * @param args - argv (never a shell string).
- * @param signal - caller/connection lifetime; abort terminates the child.
- * @returns captured stdout/stderr on exit 0.
- */
-export const runNativeCommand: NativeCommandRunner = (command, args, signal) =>
-  new Promise((resolve, reject) => {
-    execFile(
-      command,
-      [...args],
-      { encoding: 'utf8', signal, windowsHide: true },
-      (error, stdout, stderr) => {
-        if (error !== null) {
-          const failure = Object.assign(new Error(error.message, { cause: error }), {
-            code: error.code,
-            stdout,
-            stderr,
-          })
-          reject(failure)
-          return
-        }
-        resolve({ stdout, stderr })
-      },
-    )
-  })

packages/host/directory-picker-native/src/native-picker.ts

@@ -1,6 +1,6 @@
 /** Cross-platform native single-directory chooser behind the dialog backend's capability. */
 
-import { runNativeCommand, type NativeCommandRunner } from './native-command.ts'
+import { runNativeCommand, type NativeCommandRunner } from '@deepseek-ai/dsh-native-command'
 
 /** Testable command boundary; native implementations never invoke a shell. */
 export type DirectoryPickerRunner = NativeCommandRunner

packages/host/directory-picker-native/tsconfig.json

@@ -19,6 +19,9 @@
     },
     {
       "path": "../../support/invariants"
+    },
+    {
+      "path": "../../util/native-command"
     }
   ]
 }