docs: generate gitea wiki pages + publish script

add wiki/ markdown pages (Home, Sidebar, architecture, transport, developer, usage)

add scripts/publish_gitea_wiki.sh to sync wiki repo

fix: serialize aggregate env-setting tests to avoid parallel env var races

aggregate/src/config/settings.rs

@@ -205,8 +205,16 @@ mod tests {
     use super::*;
     use tempfile::tempdir;
 
+    fn env_lock() -> std::sync::MutexGuard<'static, ()> {
+        static LOCK: std::sync::OnceLock<std::sync::Mutex<()>> = std::sync::OnceLock::new();
+        LOCK.get_or_init(|| std::sync::Mutex::new(()))
+            .lock()
+            .unwrap()
+    }
+
     #[test]
     fn settings_from_env() {
+        let _guard = env_lock();
         std::env::set_var("AGGREGATE_NATS_URL", "nats://localhost:4222");
         let settings = Settings::from_env().unwrap();
         assert_eq!(settings.nats_url, "nats://localhost:4222");
@@ -224,6 +232,7 @@ mod tests {
 
     #[test]
     fn settings_from_yaml_file_and_env_override() {
+        let _guard = env_lock();
         let dir = tempdir().unwrap();
         let file_path = dir.path().join("aggregate.yaml");
         std::fs::write(