build: rebrand output artifacts to Oak and fix macOS QML deployment

- Rename macOS bundle output from Olive.app to Oak.app.
- Rename editor binary to oak-editor and render worker to oak-render-worker.
- Rename crash handler output to oak-crashhandler.
- Update worker lookup, NSIS installer, Linux desktop/AppRun, crashhandler
  symbol paths, and documentation for the new binary names.
- Update CD workflow paths and add -qmldir flags to macdeployqt so QtQuick
  / QML plugins required by KDDockWidgets are bundled, fixing the launch
  crash on macOS.
- Update user-facing GitHub URLs to OakVideoEditorCommunity/oak.

tests/gtest/render_worker_footage_test.cpp

@@ -2,7 +2,7 @@
  * Oak Video Editor - Render Worker Footage Integration Test
  * Copyright (C) 2026 Oak Team
  *
- * End-to-end test that spawns olive-render-worker, feeds it a real decoded
+ * End-to-end test that spawns oak-render-worker, feeds it a real decoded
  * frame from tests/demo.mp4 through the IPC shared-memory frame pool, and
  * verifies that the worker returns a non-black output frame.
  */
@@ -100,9 +100,9 @@ QString WorkerBinaryPath()
 	dir.cdUp();  // tests -> build dir
 	dir.cd(QStringLiteral("app"));
 #if defined(_WIN32)
-	return dir.filePath(QStringLiteral("olive-render-worker.exe"));
+	return dir.filePath(QStringLiteral("oak-render-worker.exe"));
 #else
-	return dir.filePath(QStringLiteral("olive-render-worker"));
+	return dir.filePath(QStringLiteral("oak-render-worker"));
 #endif
 }