Add type picker for entity creation, icon grid filter, and serial port placeholder

- Replace inline type selectors with pre-modal type picker grid for devices,
  color strip sources, and value sources
- Add filterable search to icon grid when items > 9 (no auto-focus on touch)
- Show disabled (grayed-out) filtered items instead of hiding them
- Responsive grid columns (2-5 cols based on viewport width)
- Add "Select a port..." placeholder to serial port dropdown
- Update en/ru/zh locales with new keys

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

server/src/wled_controller/static/locales/zh.json

@@ -112,6 +112,7 @@
   "templates.test.error.no_display": "请选择显示器",
   "templates.test.error.failed": "测试失败",
   "devices.title": "设备",
+  "device.select_type": "选择设备类型",
   "devices.add": "添加新设备",
   "devices.loading": "正在加载设备...",
   "devices.none": "尚未配置设备",
@@ -160,6 +161,7 @@
   "device.serial_port": "串口：",
   "device.serial_port.hint": "选择 Adalight 设备的 COM 端口",
   "device.serial_port.none": "未找到串口",
+  "device.serial_port.select": "选择端口...",
   "device.led_count_manual.hint": "灯带上的 LED 数量（必须与 Arduino 程序匹配）",
   "device.baud_rate": "波特率：",
   "device.baud_rate.hint": "串口通信速率。越高 FPS 越高，但需要与 Arduino 程序匹配。",
@@ -776,6 +778,7 @@
   "aria.previous": "上一个",
   "aria.next": "下一个",
   "aria.hint": "显示提示",
+  "color_strip.select_type": "选择色带类型",
   "color_strip.add": "添加色带源",
   "color_strip.edit": "编辑色带源",
   "color_strip.name": "名称：",
@@ -1128,6 +1131,7 @@
   "tree.group.picture": "图片",
   "tree.group.utility": "工具",
   "value_source.group.title": "值源",
+  "value_source.select_type": "选择值源类型",
   "value_source.add": "添加值源",
   "value_source.edit": "编辑值源",
   "value_source.name": "名称：",