AVideos has CORS Origin Reflection with Credentials on Sensitive API Endpoints that Enables Cross-Origin Account Takeover

WWBN AVideo is an open source video platform. In versions 29.0 and below, the `allowOrigin($allowAll=true)` function in `objects/functions.php` reflects any arbitrary `Origin` header back in `Access-Control-Allow-Origin` along with `Access-Control-Allow-Credentials: true`. This function is called by both `plugin/API/get.json.php` and `plugin/API/set.json.php` — the primary API endpoints that handle user data retrieval, authentication, livestream credentials, and state-changing operations. Combined with the application's `SameSite=None` session cookie policy, any website can make credentialed cross-origin requests and read authenticated API responses, enabling theft of user PII, livestream keys, and performing state changes on behalf of the victim. Commit caf705f38eae0ccfac4c3af1587781355d24495e contains a fix.