fix(dashboard): allow configuring Vite host + allowedHosts for remote serving

Users serving the dashboard from a remote VM accessed via a domain hit Vite's
host check: "Blocked request. This host ("example.com") is not allowed." (#485).
The server config hardcoded host 127.0.0.1 and set no allowedHosts, so the only
workaround was hand-editing vite.config.ts.

Add two env vars, keeping the strict localhost-only default:
- UNDERSTAND_HOST overrides the bind address (e.g. 0.0.0.0)
- UNDERSTAND_ALLOWED_HOSTS is a comma-separated allowedHosts list; `all`/`true`/`*`
  disables the check entirely

Document both in the understand-dashboard skill. The one-time access token still
gates the data endpoints. Bump version to 2.8.2.

.cursor-plugin/plugin.json

@@ -2,7 +2,7 @@
   "name": "understand-anything",
   "displayName": "Understand Anything",
   "description": "AI-powered codebase understanding — analyze, visualize, and explain any project",
-  "version": "2.8.1",
+  "version": "2.8.2",
   "author": {
     "name": "Egonex"
   },