refactor(runtime): compose consumers over fs and subprocess

packages/pty/pty-local/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@deepseek-ai/dsh-pty-local",
-  "description": "Local node-pty backend for persistent DeepSeek Harness PTY sessions",
+  "description": "Persistent shell PTY backend over the DeepSeek Harness subprocess terminal primitive",
   "version": "0.0.1",
   "private": true,
   "type": "module",
@@ -21,12 +21,8 @@
   "files": [
     "lib/index.js",
     "lib/invariant.js",
-    "scripts/ensure-spawn-helper.mjs",
     "lib/types/**/*.d.ts"
   ],
-  "scripts": {
-    "postinstall": "node scripts/ensure-spawn-helper.mjs"
-  },
   "license": "BSD-3-Clause",
   "peerDependencies": {
     "@deepseek-ai/dsh-agent": "^0.0.1",
@@ -39,7 +35,6 @@
     "cordis": "^4.0.0-rc.7"
   },
   "dependencies": {
-    "node-pty": "^1.1.0",
     "schemastery": "^3.18.0"
   },
   "devDependencies": {
@@ -50,6 +45,7 @@
     "@deepseek-ai/dsh-sandbox-policy": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-subprocess": "workspace:^",
+    "@deepseek-ai/dsh-subprocess-local": "workspace:^",
     "cordis": "^4.0.0-rc.7"
   }
 }