Remove deprecated sprite_number property from Sprite and Entity, closes #305

sprite_number was a legacy alias for sprite_index. All code should use
sprite_index directly. Removed from getsetters, setProperty/getProperty/
hasProperty in UISprite and UIEntity, animation property handling, and
type stubs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/Animation.cpp

@@ -154,13 +154,13 @@ void Animation::startEntity(std::shared_ptr<UIEntity> target) {
         }
         else if constexpr (std::is_same_v<T, int>) {
             // For entities, we might need to handle sprite_index differently
-            if (targetProperty == "sprite_index" || targetProperty == "sprite_number") {
+            if (targetProperty == "sprite_index") {
                 startValue = target->sprite.getSpriteIndex();
             }
         }
         else if constexpr (std::is_same_v<T, std::vector<int>>) {
             // For sprite animation frame lists, get current sprite index
-            if (targetProperty == "sprite_index" || targetProperty == "sprite_number") {
+            if (targetProperty == "sprite_index") {
                 startValue = target->sprite.getSpriteIndex();
             }
         }

src/Animation.h

@@ -101,7 +101,7 @@ public:
     }
     
 private:
-    std::string targetProperty;    // Property name to animate (e.g., "x", "color.r", "sprite_number")
+    std::string targetProperty;    // Property name to animate (e.g., "x", "color.r", "sprite_index")
     AnimationValue startValue;     // Starting value (captured when animation starts)
     AnimationValue targetValue;    // Target value to animate to
     float duration;                // Animation duration in seconds

src/PyAnimation.h

@@ -56,7 +56,7 @@ namespace mcrfpydef {
             "    property: Property name to animate. Valid properties depend on target type:\n"
             "        - Position/Size: 'x', 'y', 'w', 'h', 'pos', 'size'\n"
             "        - Appearance: 'fill_color', 'outline_color', 'outline', 'opacity'\n"
-            "        - Sprite: 'sprite_index', 'sprite_number', 'scale'\n"
+            "        - Sprite: 'sprite_index', 'scale'\n"
             "        - Grid: 'center', 'zoom'\n"
             "        - Caption: 'text'\n"
             "        - Sub-properties: 'fill_color.r', 'fill_color.g', 'fill_color.b', 'fill_color.a'\n"

src/UIEntity.cpp

@@ -1578,7 +1578,6 @@ PyGetSetDef UIEntity::getsetters[] = {
      "Get: Returns the Grid or None. "
      "Set: Assign a Grid to move entity, or None to remove from grid.", NULL},
     {"sprite_index", (getter)UIEntity::get_spritenumber, (setter)UIEntity::set_spritenumber, "Sprite index on the texture on the display", NULL},
-    {"sprite_number", (getter)UIEntity::get_spritenumber, (setter)UIEntity::set_spritenumber, "Sprite index (DEPRECATED: use sprite_index instead)", NULL},
     {"visible", (getter)UIEntity_get_visible, (setter)UIEntity_set_visible, "Visibility flag", NULL},
     {"opacity", (getter)UIEntity_get_opacity, (setter)UIEntity_set_opacity, "Opacity (0.0 = transparent, 1.0 = opaque)", NULL},
     {"name", (getter)UIEntity_get_name, (setter)UIEntity_set_name, "Name for finding elements", NULL},
@@ -1675,7 +1674,7 @@ bool UIEntity::setProperty(const std::string& name, float value) {
 }
 
 bool UIEntity::setProperty(const std::string& name, int value) {
-    if (name == "sprite_index" || name == "sprite_number") {
+    if (name == "sprite_index") {
         sprite.setSpriteIndex(value);
         if (grid) grid->markDirty();  // #144 - Content change
         return true;
@@ -1718,7 +1717,7 @@ bool UIEntity::hasProperty(const std::string& name) const {
         return true;
     }
     // Int properties
-    if (name == "sprite_index" || name == "sprite_number") {
+    if (name == "sprite_index") {
         return true;
     }
     // #106: Shader uniform properties - delegate to sprite

src/UISprite.cpp

@@ -406,7 +406,6 @@ PyGetSetDef UISprite::getsetters[] = {
     {"scale_x", (getter)UISprite::get_float_member, (setter)UISprite::set_float_member, "Horizontal scale factor",         (void*)3},
     {"scale_y", (getter)UISprite::get_float_member, (setter)UISprite::set_float_member, "Vertical scale factor",           (void*)4},
     {"sprite_index", (getter)UISprite::get_int_member, (setter)UISprite::set_int_member, "Which sprite on the texture is shown", NULL},
-    {"sprite_number", (getter)UISprite::get_int_member, (setter)UISprite::set_int_member, "Sprite index (DEPRECATED: use sprite_index instead)", NULL},
     {"texture", (getter)UISprite::get_texture, (setter)UISprite::set_texture,     "Texture object",                    NULL},
     {"on_click", (getter)UIDrawable::get_click, (setter)UIDrawable::set_click,
      MCRF_PROPERTY(on_click,
@@ -683,7 +682,7 @@ bool UISprite::setProperty(const std::string& name, float value) {
 }
 
 bool UISprite::setProperty(const std::string& name, int value) {
-    if (name == "sprite_index" || name == "sprite_number") {
+    if (name == "sprite_index") {
         setSpriteIndex(value);
         markDirty();  // #144 - Content change
         return true;
@@ -745,7 +744,7 @@ bool UISprite::getProperty(const std::string& name, float& value) const {
 }
 
 bool UISprite::getProperty(const std::string& name, int& value) const {
-    if (name == "sprite_index" || name == "sprite_number") {
+    if (name == "sprite_index") {
         value = sprite_index;
         return true;
     }
@@ -765,7 +764,7 @@ bool UISprite::hasProperty(const std::string& name) const {
         return true;
     }
     // Int properties
-    if (name == "sprite_index" || name == "sprite_number") {
+    if (name == "sprite_index") {
         return true;
     }
     // Vector2f properties