Purpose: companion extension for the Nexus RP Discord community (https://nexus-dev.xyz). It lets a player link their own Rockstar Social Club account to Discord.

How it works:
- background.js reads only the "BearerToken" cookie of socialclub.rockstargames.com (cookies permission) and calls the official scapi.rockstargames.com/profile/getprofile endpoint to get the signed-in user's Rockstar ID (RID) and nickname. The nickname is also read from the "authUserNickName" value embedded in Social Club pages (socialclub.js content script).
- The token never leaves the extension. Only { rid, nickname } is sent to https://nexus-dev.xyz (when the user clicks the button on our linking page, and at most once a day to /api/rockstar/contribute to feed our username -> RID directory).
- content.js runs only on nexus-dev.xyz and answers window.postMessage requests from our linking page.
- storage: stores only the last detected nickname and the last upload date.
- No remote code, no minification, no analytics, no third-party libraries.

To test: sign in to socialclub.rockstargames.com (any Rockstar account), then click the extension icon: the popup shows the nickname and RID with a "Copy RID" button.