feat(backgrounds): add starfield background with depth projection

src/locales/en.json

@@ -1157,6 +1157,8 @@
       "firefliesDesc": "Drifting glowing dots with pulsation",
       "snowfall": "Snowfall",
       "snowfallDesc": "Falling snow with wind drift",
+      "starfield": "Starfield",
+      "starfieldDesc": "Stars flying toward the viewer",
       "geminiEffect": "Gemini Effect",
       "geminiEffectDesc": "SVG effect like Google Gemini",
       "speed": "Speed",

src/locales/fa.json

@@ -1039,6 +1039,8 @@
       "firefliesDesc": "نقاط درخشان شناور با تپش",
       "snowfall": "بارش برف",
       "snowfallDesc": "برف در حال بارش با وزش باد",
+      "starfield": "میدان ستارگان",
+      "starfieldDesc": "پرواز در میان ستاره‌ها",
       "geminiEffect": "افکت Gemini",
       "geminiEffectDesc": "افکت SVG مشابه Google Gemini",
       "speed": "سرعت",

src/locales/ru.json

@@ -1187,6 +1187,8 @@
       "firefliesDesc": "Дрейфующие светящиеся точки с пульсацией",
       "snowfall": "Snowfall",
       "snowfallDesc": "Падающий снег с ветром",
+      "starfield": "Starfield",
+      "starfieldDesc": "Полёт сквозь звёздное небо",
       "geminiEffect": "Gemini Effect",
       "geminiEffectDesc": "SVG-эффект как на Google Gemini",
       "speed": "Скорость",

src/locales/zh.json

@@ -1039,6 +1039,8 @@
       "firefliesDesc": "漂浮闪烁的发光点",
       "snowfall": "降雪",
       "snowfallDesc": "随风飘落的雪花",
+      "starfield": "星空",
+      "starfieldDesc": "向观察者飞来的星星",
       "geminiEffect": "Gemini效果",
       "geminiEffectDesc": "类似Google Gemini的SVG效果",
       "speed": "速度",