[Game] Animate life counter manipulation (#7100)

* Add animations toggles for the life counter and battlefield

Per-effect toggles plus Enable/Disable-all buttons: a life-counter
flash on loss and a crimson battlefield shimmer on damage.


Took 24 seconds

* Animate life changes with a counter flash and battlefield shimmer

- Life loss/gain pulses the player life counter with a brief flash
- The battlefield table zone shimmers crimson on damage
- Respects the per-effect animation toggles

Both effects drive their decay from GameScene's shared animation timer
through the IAnimatedItem interface (QElapsedTimer based), instead of
owning per-item QTimers.

Took 8 minutes

* Revert unintentional cherry picks

Took 2 minutes

* Lambda to re-use path calculation.

Took 8 minutes

---------

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

cockatrice/src/game_graphics/player/player_target.h

@@ -7,21 +7,34 @@
 #ifndef PLAYERTARGET_H
 #define PLAYERTARGET_H
 
+#include "../animated_item.h"
 #include "../board/abstract_counter.h"
 #include "../board/arrow_target.h"
 #include "../board/graphics_item_type.h"
 
+#include <QElapsedTimer>
 #include <QPixmap>
 
 class PlayerLogic;
 
-class PlayerCounter : public AbstractCounter
+class PlayerCounter : public AbstractCounter, public IAnimatedItem
 {
     Q_OBJECT
+protected:
+    void onValueChanged(int oldValue, int newValue) override;
+
+private:
+    static constexpr qreal flashDurationMs = 450.0;
+
+    QElapsedTimer flashClock;
+    qreal flashAlpha = 0.0;
+    int flashDelta = 0;
+
 public:
     PlayerCounter(CounterState *state, PlayerLogic *player, QGraphicsItem *parent);
     QRectF boundingRect() const override;
     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override;
+    bool animationEvent() override;
 };
 
 class PlayerTarget : public ArrowTarget