fix: serialize Stripe checkout provisioning

src/config.rs

@@ -25,6 +25,7 @@ pub struct Config {
 
     pub stripe_secret_key: Option<String>,
     pub stripe_webhook_secret: Option<String>,
+    pub stripe_api_base_url: String,
 
     pub storage_path: String,
 
@@ -99,6 +100,10 @@ impl Config {
         }
         let stripe_secret_key = env_string("STRIPE_SECRET_KEY");
         let stripe_webhook_secret = env_string("STRIPE_WEBHOOK_SECRET");
+        let stripe_api_base_url = env_string("STRIPE_API_BASE_URL")
+            .unwrap_or_else(|| "https://api.stripe.com".to_string())
+            .trim_end_matches('/')
+            .to_string();
 
         let storage_path = env_string("STORAGE_PATH").unwrap_or_else(|| "./uploads".to_string());
 
@@ -140,6 +145,7 @@ impl Config {
             api_key_pepper,
             stripe_secret_key,
             stripe_webhook_secret,
+            stripe_api_base_url,
             storage_path,
             allow_anonymous_upload,
             anon_max_file_size_mb,