fix(scene): the doge collects the coins, and no more slow first lap

Three things you spotted on the History banner:

- Slow first lap that restarted at speed. The dog and the money animated
  `to: scene.width`, and the QQuickWidget starts at a placeholder width: the
  first lap crawled across the wrong distance, then the real width arrived,
  re-bound `to`, and restarted the animation. Motion is now driven by a
  unitless 0..1 progress and mapped onto the current width each frame, so a
  resize repositions without restarting.

- Coins sat mid-sky and clipped the top border. They now rest on the grass
  with a low bob, at the doge's pickup height.

- The doge collects them. A coin is collected once the doge's snout reaches
  its centre: it pops, fades, and floats a "+1". The collected state is
  derived from the run position, so the coins simply come back when the lap
  restarts, with nothing to reset.

Reduced motion still gets a static field: doge parked at the left, every coin
present, money parked in the sky.

Verified by headless qml6 render at banner (1000x140, 620x120) and lock-screen
(900x380) sizes, motion and reduced-motion, with no QML warnings.

src/widgets/IdleDoge.cpp

@@ -1,46 +0,0 @@
-// SPDX-License-Identifier: BSD-3-Clause
-// SPDX-FileCopyrightText: The Monero Project
-
-#include "IdleDoge.h"
-
-#include <QEvent>
-#include <QMovie>
-
-#include "utils/config.h"
-
-IdleDoge::IdleDoge(QWidget *parent, int height)
-    : QLabel(parent)
-    , m_movie(new QMovie(":/assets/images/dog_sitting.gif", QByteArray(), this))
-{
-    m_movie->jumpToFrame(0);
-    const QSize frame = m_movie->currentImage().size();
-    if (frame.height() > 0)
-        m_movie->setScaledSize(QSize(frame.width() * height / frame.height(), height));
-    this->setMovie(m_movie);
-    this->setAttribute(Qt::WA_TransparentForMouseEvents);   // never block the form
-    this->adjustSize();
-
-    if (conf()->get(Config::reducedMotion).toBool())
-        m_movie->jumpToFrame(0);   // still frame
-    else
-        m_movie->start();
-
-    if (parent) {
-        parent->installEventFilter(this);
-        this->reposition();
-        this->raise();
-    }
-}
-
-void IdleDoge::reposition() {
-    if (auto *p = parentWidget())
-        this->move(p->width() - this->width() - 14, p->height() - this->height() - 14);
-}
-
-bool IdleDoge::eventFilter(QObject *o, QEvent *e) {
-    if (o == parentWidget() && (e->type() == QEvent::Resize || e->type() == QEvent::Show)) {
-        this->reposition();
-        this->raise();
-    }
-    return QLabel::eventFilter(o, e);
-}

src/widgets/IdleDoge.h

@@ -1,25 +0,0 @@
-// SPDX-License-Identifier: BSD-3-Clause
-// SPDX-FileCopyrightText: The Monero Project
-
-#ifndef WOWLET_IDLEDOGE_H
-#define WOWLET_IDLEDOGE_H
-
-#include <QLabel>
-
-class QMovie;
-
-// wowlet: a small sitting doge that floats, click-through, in the bottom-right
-// corner of its parent — the "most quiet" ambient idle for task screens (Send,
-// Receive). Freezes to a still frame when "Prefer reduced motion" is set.
-class IdleDoge : public QLabel {
-Q_OBJECT
-public:
-    explicit IdleDoge(QWidget *parent, int height = 44);
-protected:
-    bool eventFilter(QObject *o, QEvent *e) override;
-private:
-    void reposition();
-    QMovie *m_movie;
-};
-
-#endif //WOWLET_IDLEDOGE_H