qt(wallet): outline the HD status letters in TRI brand red

Adds OutlinedLabel, a small QLabel subclass that paints each character
with a colored outline and a hollow interior. Used for the HD badge
in the status bar so each letter H and D is bordered in the same

- outline + fill done in custom paintEvent (no QSS hacks)
- updateHDStatus() now drives setOutlineColor/setOutlineWidth
  directly instead of stylesheets
- registered OutlinedLabel as a custom widget in mainwindow.ui
- labelHdIcon pointer type updated to OutlinedLabel*

src/qt/outlinedlabel.cpp

@@ -0,0 +1,93 @@
+#include "outlinedlabel.h"
+
+#include <QPainter>
+#include <QPainterPath>
+#include <QPaintEvent>
+#include <QStyleOption>
+#include <QTextDocument>
+#include <QString>
+
+OutlinedLabel::OutlinedLabel(QWidget* parent)
+    : QLabel(parent)
+    , m_outlineColor(QColor("#f26522"))
+    , m_outlineWidth(3)
+{
+    // OutlinedLabel is always styled; do not let QSS override our paint.
+    setAttribute(Qt::WA_OpaquePaintEvent, false);
+}
+
+void OutlinedLabel::setOutlineColor(const QColor& c)
+{
+    if (m_outlineColor == c) return;
+    m_outlineColor = c;
+    update();
+}
+
+void OutlinedLabel::setOutlineWidth(int w)
+{
+    if (m_outlineWidth == w) return;
+    m_outlineWidth = w;
+    update();
+}
+
+void OutlinedLabel::paintEvent(QPaintEvent* e)
+{
+    Q_UNUSED(e);
+
+    // Honor any background styling the parent may have given us, but
+    // do our own text rendering below. We deliberately skip QLabel's
+    // built-in drawContents/drawText path because it cannot paint a
+    // per-character outline.
+    QStyleOption opt;
+    opt.initFrom(this);
+    style()->drawPrimitive(QStyle::PE_Widget, &opt, nullptr, this);
+
+    if (text().isEmpty()) return;
+
+    QPainter painter(this);
+    painter.setRenderHint(QPainter::Antialiasing, true);
+    painter.setRenderHint(QPainter::TextAntialiasing, true);
+
+    const QFontMetricsF fm(font());
+    const QString t = text();
+    // Bounding rect for the text, honoring alignment. Add half the
+    // outline width on each side so strokes don't clip against the
+    // widget edge.
+    const qreal pad = m_outlineWidth / 2.0;
+    QRectF r = rect().adjusted(pad, pad, -pad, -pad);
+
+    // Center vertically based on font metrics
+    const qreal yOffset = (r.height() - fm.height()) / 2.0;
+    QPointF baseline(r.left(), r.top() + yOffset + fm.ascent());
+
+    // Align: use only the horizontal part of the alignment flag.
+    const int align = int(alignment() & (Qt::AlignLeft | Qt::AlignRight | Qt::AlignHCenter | Qt::AlignJustify));
+    const qreal textWidth = fm.horizontalAdvance(t);
+    qreal x = r.left();
+    if (align & Qt::AlignHCenter) {
+        x = r.left() + (r.width() - textWidth) / 2.0;
+    } else if (align & Qt::AlignRight) {
+        x = r.right() - textWidth;
+    }
+    baseline.setX(x);
+
+    QPainterPath path;
+    path.addText(baseline, font(), t);
+
+    // Stroke (outline) — drawn first, in the brand red so each letter
+    // has a clear 3px red border matching the triangle icons.
+    QPen outlinePen(m_outlineColor);
+    outlinePen.setWidth(m_outlineWidth);
+    outlinePen.setJoinStyle(Qt::RoundJoin);
+    outlinePen.setCapStyle(Qt::RoundCap);
+    painter.setPen(outlinePen);
+    painter.setBrush(Qt::NoBrush);
+    painter.drawPath(path);
+
+    // Fill the interior with the widget background color so the
+    // letters read as hollow red outlines against the dark wallet
+    // background, like the triangle icons beside them.
+    painter.setPen(Qt::NoPen);
+    painter.setBrush(QBrush(palette().color(backgroundRole())));
+    painter.drawPath(path);
+}