Implement remaining TestClient service commands (#94)

crates/libremetaverse/src/group_manager.rs

@@ -28,6 +28,11 @@ fn mutex<T>(value: &Mutex<T>) -> std::sync::MutexGuard<'_, T> {
         .lock()
         .unwrap_or_else(std::sync::PoisonError::into_inner)
 }
+fn read<T>(value: &RwLock<T>) -> std::sync::RwLockReadGuard<'_, T> {
+    value
+        .read()
+        .unwrap_or_else(std::sync::PoisonError::into_inner)
+}
 fn write<T>(value: &RwLock<T>) -> std::sync::RwLockWriteGuard<'_, T> {
     value
         .write()
@@ -260,6 +265,15 @@ impl GroupManager {
     pub fn current_group_count(&self) -> i32 {
         self.inner.group_count.load(Ordering::Acquire)
     }
+
+    /// Returns a stable snapshot of the groups currently reported for this agent.
+    ///
+    /// The cache is replaced atomically whenever an `AgentGroupDataUpdate` arrives,
+    /// so callers never observe a partially decoded group list.
+    #[must_use]
+    pub fn current_groups(&self) -> HashMap<UUID, Group> {
+        read(&self.inner.groups).clone()
+    }
     pub fn group_membership_limit(&self) -> i32 {
         let mut client = (*self.inner.client).clone();
         client.self_().benefits().group_membership_limit()