Add HTTP client wrapper and upgrade Axios to v1 (#594)

* refactor: add HTTP client wrapper and upgrade axios to v1

Introduce a thin HTTP wrapper (resources/scripts/http) that centralizes
axios configuration, interceptors, and auth header injection. All 43
files now import from the wrapper instead of axios directly, making
future library swaps a single-file change. Upgrade axios from 0.30.0
to 1.14.0.

* fix: restore window.Ls assignment removed during axios refactor

company.js uses window.Ls.set() to persist selected company,
which broke after the axios plugin (that set window.Ls) was deleted.

resources/scripts/plugins/axios.js

@@ -1,31 +0,0 @@
-import axios from 'axios'
-import Ls from '@/scripts/services/ls.js'
-
-window.Ls = Ls
-window.axios = axios
-axios.defaults.withCredentials = true
-
-axios.defaults.headers.common = {
-  'X-Requested-With': 'XMLHttpRequest',
-}
-
-/**
- * Interceptors
- */
-
-axios.interceptors.request.use(function (config) {
-  // Pass selected company to header on all requests
-  const companyId = Ls.get('selectedCompany')
-
-  const authToken = Ls.get('auth.token')
-
-  if (authToken) {
-    config.headers.Authorization = authToken
-  }
-
-  if (companyId) {
-    config.headers.company = companyId
-  }
-
-  return config
-})