Add primary display indicator, custom accent color picker, restart script

- Detect primary monitor via Windows EnumDisplayMonitors API and show badge
- Expand accent color picker with 9 presets and custom color input
- Auto-generate hover color for custom accent colors
- Re-render accent swatches on locale change for proper i18n
- Replace restart-server.bat with PowerShell restart-server.ps1

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

media_server/services/display_service.py

@@ -1,5 +1,7 @@
 """Display brightness and power control service."""
 
+import ctypes
+import ctypes.wintypes
 import logging
 import platform
 import struct
@@ -61,6 +63,7 @@ class MonitorInfo:
     model: str = ""
     manufacturer: str = ""
     resolution: str | None = None
+    is_primary: bool = False
 
     def to_dict(self) -> dict:
         return {
@@ -72,9 +75,68 @@ class MonitorInfo:
             "model": self.model,
             "manufacturer": self.manufacturer,
             "resolution": self.resolution,
+            "is_primary": self.is_primary,
         }
 
 
+def _detect_primary_resolution() -> str | None:
+    """Detect the primary display resolution via Windows API."""
+    if platform.system() != "Windows":
+        return None
+    try:
+        class MONITORINFO(ctypes.Structure):
+            _fields_ = [
+                ("cbSize", ctypes.wintypes.DWORD),
+                ("rcMonitor", ctypes.wintypes.RECT),
+                ("rcWork", ctypes.wintypes.RECT),
+                ("dwFlags", ctypes.wintypes.DWORD),
+            ]
+
+        MONITORINFOF_PRIMARY = 1
+        primary_res = None
+
+        def callback(hmon, hdc, rect, data):
+            nonlocal primary_res
+            mi = MONITORINFO()
+            mi.cbSize = ctypes.sizeof(mi)
+            ctypes.windll.user32.GetMonitorInfoW(hmon, ctypes.byref(mi))
+            if mi.dwFlags & MONITORINFOF_PRIMARY:
+                w = mi.rcMonitor.right - mi.rcMonitor.left
+                h = mi.rcMonitor.bottom - mi.rcMonitor.top
+                primary_res = f"{w}x{h}"
+            return True
+
+        MONITORENUMPROC = ctypes.WINFUNCTYPE(
+            ctypes.c_int,
+            ctypes.wintypes.HMONITOR,
+            ctypes.wintypes.HDC,
+            ctypes.POINTER(ctypes.wintypes.RECT),
+            ctypes.wintypes.LPARAM,
+        )
+        ctypes.windll.user32.EnumDisplayMonitors(
+            None, None, MONITORENUMPROC(callback), 0
+        )
+        return primary_res
+    except Exception:
+        return None
+
+
+def _mark_primary(monitors: list[MonitorInfo]) -> None:
+    """Mark the primary display in the monitor list."""
+    if not monitors:
+        return
+
+    primary_res = _detect_primary_resolution()
+    if primary_res:
+        for m in monitors:
+            if m.resolution == primary_res:
+                m.is_primary = True
+                return
+
+    # Fallback: mark first monitor as primary
+    monitors[0].is_primary = True
+
+
 # Cache for monitor list
 _monitor_cache: list[MonitorInfo] | None = None
 _cache_time: float = 0
@@ -142,6 +204,7 @@ def list_monitors(force_refresh: bool = False) -> list[MonitorInfo]:
     except Exception as e:
         logger.error("Failed to enumerate monitors: %s", e)
 
+    _mark_primary(monitors)
     _monitor_cache = monitors
     _cache_time = time.time()
     return monitors