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/en.json

@@ -112,6 +112,7 @@
   "templates.test.error.no_display": "Please select a display",
   "templates.test.error.failed": "Test failed",
   "devices.title": "Devices",
+  "device.select_type": "Select Device Type",
   "devices.add": "Add New Device",
   "devices.loading": "Loading devices...",
   "devices.none": "No devices configured",
@@ -211,6 +212,7 @@
   "device.serial_port": "Serial Port:",
   "device.serial_port.hint": "Select the COM port of the Adalight device",
   "device.serial_port.none": "No serial ports found",
+  "device.serial_port.select": "Select a port...",
   "device.led_count_manual.hint": "Number of LEDs on the strip (must match your Arduino sketch)",
   "device.baud_rate": "Baud Rate:",
   "device.baud_rate.hint": "Serial communication speed. Higher = more FPS but requires matching Arduino sketch.",
@@ -827,6 +829,7 @@
   "aria.previous": "Previous",
   "aria.next": "Next",
   "aria.hint": "Show hint",
+  "color_strip.select_type": "Select Color Strip Type",
   "color_strip.add": "Add Color Strip Source",
   "color_strip.edit": "Edit Color Strip Source",
   "color_strip.name": "Name:",
@@ -1179,6 +1182,7 @@
   "tree.group.picture": "Picture",
   "tree.group.utility": "Utility",
   "value_source.group.title": "Value Sources",
+  "value_source.select_type": "Select Value Source Type",
   "value_source.add": "Add Value Source",
   "value_source.edit": "Edit Value Source",
   "value_source.name": "Name:",