OTA steps 3-5: Update Service, Probation and Rollback, Update from SD

- EcdsaVerifier (mbedTLS, embedded public key) and EspOtaSink (writes
  the inactive app slot, esp_ota_end validates the image, then sets
  the boot partition)
- UpdateService: listens on TCP 3232 (and mDNS roro9stack-<id>) while
  Wi-Fi is Connected; streams into UpdateParser; replies OK/ERR to the
  sender; remembers the pending version so a Rollback is reported
  after the reboot
- Probation (host-tested): confirm after the first frame + 30 s + Wi-Fi
  (if configured); roll back if configured Wi-Fi never connects in 3 min
- Main loop: full-screen progress while receiving; restart once
  installed, waiting up to 60 s for Text Entry to end
- Settings > Firmware: version, Probation status, push address and
  name, and the .ota files in /updates on the SD card to install
- StorageService.runJob() runs work on the storage task (SD installs)
- wifi status prints IP and running version; RORO_TEST_CRASH test hook

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

src/apps/firmware_page.h

@@ -0,0 +1,47 @@
+#pragma once
+
+#include <memory>
+#include <mutex>
+#include <string>
+#include <vector>
+
+#include "dialog_model.h"
+#include "key_event.h"
+#include "list_model.h"
+#include "services/storage_service.h"
+#include "services/update_service.h"
+#include "services/wifi_service.h"
+#include "ui/canvas.h"
+#include "ui/theme.h"
+
+namespace roro {
+
+// Settings → Firmware: the running version and its Probation, where to push Firmware Updates, and
+// the Update Files on the SD card (in /updates) to install from.
+class FirmwarePage {
+   public:
+    FirmwarePage(UpdateService& update, WifiService& wifi, StorageService& storage)
+        : update_(update), wifi_(wifi), storage_(storage) {}
+
+    void enter();
+    bool onKey(const KeyEvent& e);  // false: leave the page
+    void draw(Canvas& c);
+
+   private:
+    enum Row { kVersion, kStatus, kAddress, kName, kSdHeader, kFixed };
+
+    std::vector<std::string> files();
+
+    UpdateService& update_;
+    WifiService& wifi_;
+    StorageService& storage_;
+    ListModel list_{theme::kContent.h / theme::kLineHeight};
+    std::unique_ptr<DialogModel> confirm_;
+
+    // Filled on the storage task.
+    std::mutex lock_;
+    std::vector<std::string> files_;
+    bool listed_ = false;
+};
+
+}  // namespace roro