M0 step 7: Settings, About, Storage, first-boot setup

- lib/apps_model (host-tested): SettingsMenu (rows, readable values,
  choices, validation messages) and SetupWizard (names, Region
  confirmation, timezone; saves only when finished)
- AppManager: modal Apps that Home/Back can't leave (setup wizard)
- SettingsApp: all settings plus Storage (usage, erase SD behind a
  dialog) and About (version, node id, battery, memory, uptime) pages,
  replacing the temporary Diagnostics App
- SetupApp: first-boot wizard, opened modally until SetupDone
- Node id and default names derived from the MAC like Meshtastic
- Widget demo is now hidden (About, then w)
- lib_ldf_mode = deep+ so libraries see each other's headers

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

src/apps/settings_app.h

@@ -0,0 +1,62 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "app.h"
+#include "app_manager.h"
+#include "dialog_model.h"
+#include "event_bus.h"
+#include "line_editor.h"
+#include "list_model.h"
+#include "services/battery_service.h"
+#include "services/clock_service.h"
+#include "services/storage_service.h"
+#include "settings_menu.h"
+#include "ui/theme.h"
+
+namespace roro {
+
+struct SettingsAppDeps {
+    Settings& settings;
+    EventBus& bus;
+    AppManager& apps;
+    BatteryService& battery;
+    StorageService& storage;
+    ClockService& clock;
+};
+
+// Settings: every user-facing setting, plus the Storage and About pages.
+class SettingsApp : public App {
+   public:
+    explicit SettingsApp(const SettingsAppDeps& deps) : d_(deps), menu_(deps.settings) {}
+    void onEnter() override;
+    bool onKey(const KeyEvent& e) override;
+    void update(uint32_t nowMs) override;
+    void draw(Canvas& c) override;
+
+   private:
+    enum class Page { Menu, Text, Choice, Storage, About };
+
+    bool onMenuKey(const KeyEvent& e);
+    bool onTextKey(const KeyEvent& e);
+    bool onChoiceKey(const KeyEvent& e);
+    bool onStorageKey(const KeyEvent& e);
+    bool onAboutKey(const KeyEvent& e);
+    void warn(const std::string& text);
+    std::vector<std::string> storageLines() const;
+    std::vector<std::string> aboutLines() const;
+
+    SettingsAppDeps d_;
+    SettingsMenu menu_;
+    Page page_ = Page::Menu;
+    ListModel list_{theme::kContent.h / theme::kLineHeight};
+    ListModel choices_{theme::kContent.h / theme::kLineHeight};
+    LineEditor editor_{39};
+    std::unique_ptr<DialogModel> eraseDialog_;
+    int editingRow_ = 0;
+    uint32_t lastRefreshMs_ = 0;
+};
+
+}  // namespace roro