container: root: macros: add Pluggable support

- Adds requirements to support auto-(un)load'ing, refactors

- Adds loader argument to unit tests and benchmarks
  * Filters can now be passed as a loader argument

- Adds loader argument to Hash macro
  * Factored out from shell caller

container/src/root/macro/test/unit.C

@@ -1,6 +1,6 @@
 // docker-finance | modern accounting for the power-user
 //
-// Copyright (C) 2021-2025 Aaron Fiore (Founder, Evergreen Crypto LLC)
+// Copyright (C) 2021-2026 Aaron Fiore (Founder, Evergreen Crypto LLC)
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU General Public License as published by
@@ -61,24 +61,57 @@ class Unit
 
  public:
   //! \brief Macro for running all tests
-  //! \todo parameter arg that takes list of tests
-  static int run()
+  static int run(const std::string& arg)
   {
-    static bool loaded{false};
-    static const std::initializer_list<std::string> paths{
-        {"test/unit/hash.hh"},
-        {"test/unit/random.hh"},
-        {"test/unit/type.hh"},
-        {"test/unit/utility.hh"}};
+    ::testing::GTEST_FLAG(filter) = arg.empty() ? "*" : arg;
+    return RUN_ALL_TESTS();
+  }
 
-    if (!loaded)
-      {
-        ::dfi::common::Command::load(paths);
-        loaded = true;
-      }
+ public:
+  static constexpr std::initializer_list<std::string_view> m_paths{
+      {"test/unit/hash.hh"},
+      {"test/unit/random.hh"},
+      {"test/unit/type.hh"},
+      {"test/unit/utility.hh"}};
+};
+
+//! \brief Pluggable entrypoint
+//! \ingroup cpp_macro_impl
+//! \since docker-finance 1.1.0
+class unit_C final
+{
+ public:
+  unit_C() = default;
+  ~unit_C() = default;
+
+  unit_C(const unit_C&) = default;
+  unit_C& operator=(const unit_C&) = default;
+
+  unit_C(unit_C&&) = default;
+  unit_C& operator=(unit_C&&) = default;
+
+ public:
+  //! \brief Macro auto-loader
+  //! \param arg GoogleTest regex filter
+  static void load(const std::string& arg = {})
+  {
+    for (auto path : Unit::m_paths)
+      ::dfi::common::load(std::string{path});
 
     ::testing::InitGoogleTest();
-    return RUN_ALL_TESTS();  // TODO(unassigned): caller do something about this
+
+    Unit::run(arg);
+  }
+
+  //! \brief Macro auto-unloader
+  //! \param arg Optional code to execute before unloading
+  static void unload(const std::string& arg = {})
+  {
+    if (!arg.empty())
+      ::dfi::common::line(arg);
+
+    for (auto path : Unit::m_paths)
+      ::dfi::common::unload(std::string{path});
   }
 };
 }  // namespace test