[Icons] Migrate UI glyphs to palette-token SVGs (#7595)

* [Icons] Migrate UI glyphs to palette-token SVGs

Runtime inversion is not a theming system: it rotates hue, breaks duotone art
and mishandles alpha, and a QPixmap snapshot cannot follow a palette change.
Redraw the top-level UI glyph set on a 24x24 grid with `currentColor` as the
paint token, drop Inkscape/Sodipodi cruft, and delete the icons whose metaphor
was duplicated (cogwheel/gear -> settings, scale_balanced -> scales,
update.png -> reload).

Load the glyphs through `loadThemedIcon` so the engine resolves the token from
the palette on every request, and let `themePixmap` use the same resolution for
one-shot pixmaps. `loadColorAdjustedPixmap` is gone; every caller now keeps a
QIcon, which `SettingsButtonWidget::setButtonIcon` accepts instead of a QPixmap.

Content art (mana, counters, countries) keeps its authored colors.

Add a render test covering aspect ratio, palette flips, icon modes and
high-DPI pixmaps.

* [Tests] Keep the icon render test QApplication alive until exit

Creating it as a function-local static tears it down before Qt's library statics
at exit, and libQt6Network then runs QObject destructors against freed memory —
a SEGV the sanitizer leg reports after the tests have already passed. Leak the
application instead, the usual pattern for a test binary.

* [Icons] Render lock and dropdown glyphs through the icon engine

Both generators rendered the sentinel SVG to a fixed height x height pixmap
at DPR 1. The pre-migration path rendered larger and let QIcon scale it, so
on a 2x display the games-list lock (13px) and the banner dropdown arrow
(24px) came back crisp; the new path hands the widget a DPR-1 bitmap that
gets upscaled and blurred.

- The games list asks the themed engine for `icons/lock` directly, so the
  item view paints it at the device pixel ratio and the lock also follows
  HighlightedText on a selected row.
- The dropdown goes through `loadThemedIcon(...).pixmap(size, dpr)`, which
  keeps the glyph's aspect ratio and renders at the requested ratio.
- LockPixmapGenerator has no consumer left, so it and its cache are gone.

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/game_graphics/player/player_list_widget.cpp

@@ -1,6 +1,7 @@
 #include "player_list_widget.h"
 
 #include "../../interface/pixel_map_generator.h"
+#include "../../interface/theme_icon.h"
 #include "../../interface/widgets/server/user/user_context_menu.h"
 #include "libcockatrice/protocol/pb/serverinfo_user.pb.h"
 #include "user_level.h"
@@ -67,13 +68,13 @@ PlayerListWidget::PlayerListWidget(TabSupervisor *_tabSupervisor,
                                    QWidget *parent)
     : QTreeWidget(parent), tabSupervisor(_tabSupervisor), client(_client), game(_game), gameStarted(false)
 {
-    readyIcon = themePixmap(QStringLiteral("icons/ready_start"));
-    notReadyIcon = themePixmap(QStringLiteral("icons/not_ready_start"));
-    concededIcon = themePixmap(QStringLiteral("icons/conceded"));
-    playerIcon = loadColorAdjustedPixmap("theme:icons/player");
-    judgeIcon = loadColorAdjustedPixmap("theme:icons/scales");
-    spectatorIcon = loadColorAdjustedPixmap("theme:icons/spectator");
-    lockIcon = themePixmap(QStringLiteral("icons/lock"));
+    readyIcon = loadThemedIcon(QStringLiteral("icons/ready_start"));
+    notReadyIcon = loadThemedIcon(QStringLiteral("icons/not_ready_start"));
+    concededIcon = loadThemedIcon(QStringLiteral("icons/conceded"));
+    playerIcon = loadThemedIcon(QStringLiteral("icons/player"));
+    judgeIcon = loadThemedIcon(QStringLiteral("icons/scales"));
+    spectatorIcon = loadThemedIcon(QStringLiteral("icons/spectator"));
+    lockIcon = loadThemedIcon(QStringLiteral("icons/lock"));
 
     if (tabSupervisor) {
         itemDelegate = new PlayerListItemDelegate(this);