implement mod delete functions

app/Http/Controllers/ModController.php

@@ -55,5 +55,10 @@ class ModController extends Controller
         return new ModResource($mod);
     }
 
-    public function destroy(Mod $mod): void {}
+    public function destroy(Mod $mod): void
+    {
+        $this->authorize('delete', $mod);
+
+        $mod->delete();
+    }
 }

app/Policies/ModPolicy.php

@@ -45,7 +45,10 @@ class ModPolicy
      */
     public function delete(User $user, Mod $mod): bool
     {
-        return false;
+        // I'm guessing we want the mod author to also be able to do this?
+        // what if there are multiple authors?
+        // I'm leaving that out for now -waffle.lazy
+        return $user->isMod() || $user->isAdmin();
     }
 
     /**