One firmware: the Debug Console in every build, off until switched on, with the device's own token

There is no Debug Build any more (ADR 0010, issue #68, Q188 to Q195). The
console and the test commands are compiled into every firmware. It listens
only while Settings > Debug Console is on, which isn't the default; off,
neither its task nor its 4 KB ring exists. The token is made by the device
and shown on that page; a client proves it knows it by answering a challenge
with an HMAC, so it never crosses the network, and five wrong answers close
the console for a minute. DBG in the Status Bar while it listens.

Over USB serial only: debug on, debug token <value>, debug token new.
scripts/flash.sh --debug uses them to set a device up with the developer's
token. scripts/rdbg.py takes the token from -t, $RORO_DEBUG_TOKEN or the
file, answers the challenge, and fetches a release's ELF to decode a crash.

Gone: the cardputer-adv-debug environment, RORO_DEBUG, the +debug version,
scripts/debug_flags.py, update install ... force, and the rule that a Debug
Build doesn't install releases. Old clients and old firmwares don't talk to
each other.

Against the builds it replaces: 30 KB more flash and 88 bytes more static
RAM than the release, 4 KB less RAM than the Debug Build. 468 host tests.
Checked on the device: off by default, login, the pause after wrong tokens,
Safe Mode with the console, the setting surviving an update, debug off.

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

src/apps/debug_console_page.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <memory>
+#include <string>
+
+#include "dialog_model.h"
+#include "key_event.h"
+#include "line_editor.h"
+#include "list_model.h"
+#include "services/wifi_service.h"
+#include "settings.h"
+#include "ui/canvas.h"
+#include "ui/theme.h"
+
+namespace roro {
+
+// Settings → Debug Console (ADR 0010): the switch, where to connect, and the token, which is shown
+// here and nowhere else. Switching on makes a token if there's none; a new one, or one typed by
+// hand, ends the connection of whoever holds the old one.
+class DebugConsolePage {
+   public:
+    DebugConsolePage(Settings& settings, WifiService& wifi) : settings_(settings), wifi_(wifi) {}
+
+    void enter();
+    bool onKey(const KeyEvent& e);  // false: leave the page
+    bool textEntryActive() const { return typing_; }
+    void draw(Canvas& c);
+
+   private:
+    enum Row { kSwitch, kAddress, kNewToken, kTypeToken, kRows };
+    enum class Ask { None, SwitchOn, NewToken };
+
+    Settings& settings_;
+    WifiService& wifi_;
+    ListModel list_{kRows};
+    std::unique_ptr<DialogModel> confirm_;
+    Ask ask_ = Ask::None;
+    bool typing_ = false;
+    LineEditor editor_{64};
+    std::string refusal_;
+};
+
+}  // namespace roro