refactor: refactor subscription delivery logic, change payment return_url to origin_url concatenation

- Unify protocol filter configuration to client.type.field (dot-path, three-segment) format, support strict whitelist mode
- Refactor AbstractProtocol and all protocol classes for more flexible and maintainable subscription delivery
- Change payment callback logic: use origin_url concatenation instead of return_url for more accurate redirects

app/Protocols/Shadowsocks.php

@@ -3,11 +3,16 @@
 namespace App\Protocols;
 
 use App\Support\AbstractProtocol;
+use App\Models\Server;
 
 class Shadowsocks extends AbstractProtocol
 {
     public $flags = ['shadowsocks'];
 
+    public $allowedProtocols = [
+        Server::TYPE_SHADOWSOCKS,
+    ];
+
     public function handle()
     {
         $servers = $this->servers;