feat(19.3-06): purge route accepts proxied requests on siteCache.allowProxied (WR-03)

- runtimeConfig.siteCache.allowProxied (NUXT_SITE_CACHE_ALLOW_PROXIED, default
  false) lets the shared purge route accept a request that came through a
  TLS-terminating proxy; the bearer token is then the only gate
- shared lib, route and spec stay byte-identical across the three layers,
  with updated sha256 pins and two new sitePurge specs

- version 0.5.0

package.json

@@ -1,6 +1,6 @@
 {
   "name": "vue-journal-layer",
-  "version": "0.4.0",
+  "version": "0.5.0",
   "private": true,
   "type": "module",
   "main": "./nuxt.config.ts",