Merge remote-tracking branch 'origin/master' into codex/wechat-mini-program-virtual-payment

# Conflicts:
#	.hermes/shared-memory/decision-log.md

server-rs/crates/module-auth/src/domain.rs

@@ -237,6 +237,22 @@ pub fn build_system_username(prefix: &str, sequence: u64) -> String {
     format!("{prefix}_{sequence:08}")
 }
 
+pub fn build_wechat_username(display_name: &str, provider_uid: &str) -> String {
+    let normalized_display_name = display_name.trim();
+    let normalized_provider_uid = provider_uid.trim();
+    let fallback_display_name = if normalized_display_name.is_empty() {
+        "微信旅人"
+    } else {
+        normalized_display_name
+    };
+    let fallback_provider_uid = if normalized_provider_uid.is_empty() {
+        "openid"
+    } else {
+        normalized_provider_uid
+    };
+    format!("{fallback_display_name}_{fallback_provider_uid}")
+}
+
 // 公开陶泥号是稳定的公开检索键，不替代内部 user_id，仅用于展示、分享与搜索。
 pub fn build_public_user_code(sequence: u64) -> String {
     format!("SY-{sequence:08}")