9router: Reverse proxy locality collapse allows unauthenticated access to 9router /v1 APIs

9Router is an AI router & token saver. Prior to 0.5.2, 9router treats loopback requests as trusted and allows /v1/* access without an API key, so a same-host reverse proxy that forwards public traffic to the backend through 127.0.0.1 causes src/dashboardGuard.js to misclassify external requests as local. A remote unauthenticated attacker can access /v1 APIs such as /v1/models and may abuse configured upstream provider credentials through /v1 proxy endpoints depending on enabled providers. This issue is fixed in version 0.5.2.