fix(ui): reset webpack.config.js service on correct CWD, closes #1555

packages/@vue/cli-service/webpack.config.js

@@ -3,7 +3,7 @@
 
 let service = process.VUE_CLI_SERVICE
 
-if (!service) {
+if (!service || process.env.VUE_CLI_API_MODE) {
   const Service = require('./lib/Service')
   service = new Service(process.env.VUE_CLI_CONTEXT || process.cwd())
   service.init(process.env.VUE_CLI_MODE || process.env.NODE_ENV)

packages/@vue/cli-ui/src/graphql-api/connectors/cwd.js

@@ -6,6 +6,7 @@ module.exports = {
   get: () => cwd,
   set: (value, context) => {
     cwd = value
+    process.env.VUE_CLI_CONTEXT = value
     context.pubsub.publish(channels.CWD_CHANGED, { cwdChanged: value })
     try {
       process.chdir(value)

packages/@vue/cli-ui/src/graphql-api/connectors/projects.js

@@ -246,6 +246,7 @@ async function create (input, context) {
     })
 
     const targetDir = path.join(cwd.get(), input.folder)
+    cwd.set(targetDir, context)
     creator.context = targetDir
 
     const inCurrent = input.folder === '.'