Add display refresh rate detection and display

- Added get_monitor_refresh_rates() function in monitor_names.py using Windows ctypes/DEVMODE to detect monitor refresh rates
- Updated DisplayInfo dataclass and Pydantic schema to include refresh_rate field (in Hz)
- Modified get_available_displays() to detect and include refresh rates (defaults to 60Hz on non-Windows or if detection fails)
- Added refresh rate display in Web UI between Resolution and Position
- Added translations for refresh rate label (displays.refresh_rate) in English and Russian locales
- Cross-platform compatible: gracefully falls back to 60Hz default on non-Windows systems

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

server/src/wled_controller/api/schemas.py

@@ -36,6 +36,7 @@ class DisplayInfo(BaseModel):
     x: int = Field(description="Display X position")
     y: int = Field(description="Display Y position")
     is_primary: bool = Field(default=False, description="Whether this is the primary display")
+    refresh_rate: int = Field(description="Display refresh rate in Hz")
 
 
 class DisplayListResponse(BaseModel):