style: unify identifier naming per updated conventions

Automated with clang-tidy readability-identifier-naming (config added to
.clang-tidy) plus scripted passes, per the updated rules now documented
in CONTRIBUTING.md:

- types (class/struct/enum/alias/template params): PascalCase
- functions, variables, members: snake_case (incl. rational -> Rational)
- private/protected members: trailing underscore; static member
  variables likewise (instance_, available_themes_)
- constants and enum values: snake_case (kLinear -> k_linear,
  F32P -> f32p); ALL_CAPS reserved for macros
- macros: OAK_ prefix (OLIVE_ADD_TEST/OLIVE_ASSERT/OLIVE_CONFIG ->
  OAK_ADD_TEST/OAK_ASSERT/OAK_CONFIG, GL_PREAMBLE -> OAK_GL_PREAMBLE,
  include guards -> OAK_*)
- file names: all lowercase (Current/Plugin/OliveHost/OliveClip/
  OlivePluginInstance -> current/plugin/olivehost/oliveclip/
  oliveplugininstance)
- getters share the member name sans underscore, setters set_foo()
- Qt and third-party (OpenFX) virtual overrides and framework callbacks
  keep their original names (exempt in .clang-tidy)

Manual follow-ups required where automation could not reach:
- string-based QMetaObject/SIGNAL/SLOT references updated to renamed
  methods (AddTask, CreatedFile, DeleteSpecificFile, moveSelectionUp, ...)
- macro bodies referencing renamed methods (OLIVE_CONFIG,
  NODE_DEFAULT_DESTRUCTOR, MANAGEDDISPLAYWIDGET_*)
- self-shadowing locals renamed where signals/methods became same-named
  (size_changed, worker_count, selected_items, import param, filters)
- third_party OFX member/namespace usages restored (OFX::Host::*,
  _created, _clipPrefsDirty, createInstance, clearPersistentMessage)
- STL protocol aliases restored (const_iterator) with .clang-tidy
  ignore rules; qHash overloads restored

Full build and test suite pass: ctest 4/4, ~1960 gtest cases green.

tests/gtest/node_view_test.cpp

@@ -12,10 +12,10 @@ class NodeViewTest : public ::testing::Test {
 protected:
 	void SetUp() override
 	{
-		ColorManager::SetUpDefaultConfig();
+		ColorManager::set_up_default_config();
 
 		project_ = std::make_unique<Project>();
-		project_->Initialize();
+		project_->initialize();
 	}
 
 	std::unique_ptr<Project> project_;
@@ -24,8 +24,8 @@ protected:
 TEST_F(NodeViewTest, ConstructionCreatesEmptyView)
 {
 	NodeView view;
-	EXPECT_TRUE(view.GetContexts().isEmpty());
-	EXPECT_FALSE(view.IsGroupOverlay());
+	EXPECT_TRUE(view.get_contexts().isEmpty());
+	EXPECT_FALSE(view.is_group_overlay());
 }
 
 TEST_F(NodeViewTest, SetContextsUpdatesContextList)
@@ -34,10 +34,10 @@ TEST_F(NodeViewTest, SetContextsUpdatesContextList)
 	solid->setParent(project_.get());
 
 	NodeView view;
-	view.SetContexts({ solid });
+	view.set_contexts({ solid });
 
-	EXPECT_EQ(view.GetContexts().size(), 1);
-	EXPECT_EQ(view.GetContexts().first(), solid);
+	EXPECT_EQ(view.get_contexts().size(), 1);
+	EXPECT_EQ(view.get_contexts().first(), solid);
 }
 
 TEST_F(NodeViewTest, ShowSelectedNodeInParamEditorNoSelectionIsNoOp)
@@ -45,7 +45,7 @@ TEST_F(NodeViewTest, ShowSelectedNodeInParamEditorNoSelectionIsNoOp)
 	NodeView view;
 
 	QSignalSpy changed_with_ctx_spy(
-		&view, &NodeView::NodeSelectionChangedWithContexts);
+		&view, &NodeView::node_selection_changed_with_contexts);
 
 	// The action must exist; silently skipping the trigger would make this
 	// test pass without exercising anything
@@ -71,9 +71,9 @@ TEST_F(NodeViewTest, ClearGraphRemovesContexts)
 	solid->setParent(project_.get());
 
 	NodeView view;
-	view.SetContexts({ solid });
-	EXPECT_FALSE(view.GetContexts().isEmpty());
+	view.set_contexts({ solid });
+	EXPECT_FALSE(view.get_contexts().isEmpty());
 
-	view.ClearGraph();
-	EXPECT_TRUE(view.GetContexts().isEmpty());
+	view.clear_graph();
+	EXPECT_TRUE(view.get_contexts().isEmpty());
 }