Add Borealis GUI for patch extraction on Switch.

Replace the console UI with a Borealis-based flow, bundle ROMFS assets and
borealis as a submodule, and apply small upstream patches at build time.
Self-delete runs after romfsExit on quit so the NRO can be removed like the
old console build.

source/patch_activity.hpp

@@ -0,0 +1,39 @@
+#pragma once
+
+#include <borealis.hpp>
+#include <memory>
+
+#include "extractor.hpp"
+
+class PatchActivity : public brls::Activity {
+public:
+    PatchActivity();
+    ~PatchActivity() override;
+
+    brls::View* createContentView() override;
+    void onContentAvailable() override;
+
+private:
+    enum class Screen { Error, Ready, Extracting, Done };
+
+    void showScreen(Screen screen);
+    void startExtraction();
+    void onExtractTick();
+    void updateProgressUi();
+    bool onExtractClicked(brls::View* view);
+
+    brls::AppletFrame* frame = nullptr;
+    brls::Box* contentBox = nullptr;
+
+    brls::Label* titleLabel = nullptr;
+    brls::Label* messageLabel = nullptr;
+    brls::Label* detailLabel = nullptr;
+    brls::Label* progressLabel = nullptr;
+    brls::Box* progressTrack = nullptr;
+    brls::Rectangle* progressFill = nullptr;
+    brls::Button* actionButton = nullptr;
+
+    std::unique_ptr<PatchExtractor> extractor;
+    brls::RepeatingTimer extractTimer;
+    Screen currentScreen = Screen::Ready;
+};