Write out the high-level API I need.

SpaceWizards.Sodium/SodiumCore.cs

@@ -0,0 +1,26 @@
+using static SpaceWizards.Sodium.Interop.Libsodium;
+
+namespace SpaceWizards.Sodium;
+
+public static class SodiumCore
+{
+    /// <summary>
+    /// Directly call <see cref="sodium_init"/>.
+    /// </summary>
+    /// <returns>0 on success, 1 if already initialized, -1 on initialize failure.</returns>
+    /// <seealso cref="EnsureInit"/>
+    public static int Init()
+    {
+        return sodium_init();
+    }
+
+    /// <summary>
+    /// Try to ensure libsodium is initialized, throwing if it fails to initialize.
+    /// </summary>
+    /// <exception cref="SodiumInitException">Thrown if initialization of libsodium failed.</exception>
+    public static void EnsureInit()
+    {
+        if (Init() == -1)
+            throw new SodiumInitException("Failed to init libsodium!");
+    }
+}