chore(release): keep SFU sidecar download on Forgejo (git.blax.at), not GitHub

We host the canonical package on our own Forgejo for independence; Packagist
indexes it from there. The prebuilt binary ships committed in rust/dist/ and is
resolved before any download, so this URL is only the cross-platform fallback.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

config/webrtc.php

@@ -68,12 +68,12 @@ return [
         'version' => env('WEBRTC_SFU_VERSION'), // default: the version pinned by this package
         'download_url' => env(
             'WEBRTC_SFU_DOWNLOAD_URL',
-            'https://github.com/blax-software/laravel-webrtc/releases/download/{version}/blax-webrtc-sfu-{platform}',
+            'https://git.blax.at/blax-software/laravel-webrtc/releases/download/{version}/blax-webrtc-sfu-{platform}',
         ),
         // sha256 verification is REQUIRED when set; null opts out explicitly.
         'checksum_url' => env(
             'WEBRTC_SFU_CHECKSUM_URL',
-            'https://github.com/blax-software/laravel-webrtc/releases/download/{version}/blax-webrtc-sfu-{platform}.sha256',
+            'https://git.blax.at/blax-software/laravel-webrtc/releases/download/{version}/blax-webrtc-sfu-{platform}.sha256',
         ),
     ],