Add Daylight Cycle value source type

New value source that outputs brightness (0-1) based on the daylight
color LUT, computing BT.601 luminance from the simulated sky color.
Supports real-time wall-clock mode or configurable simulation speed.

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

server/src/wled_controller/storage/value_source.py

@@ -1,13 +1,14 @@
 """Value source data model with inheritance-based source types.
 
 A ValueSource produces a scalar float (0.0–1.0) that can drive target
-parameters like brightness.  Five types:
+parameters like brightness.  Six types:
   StaticValueSource    — constant float value
   AnimatedValueSource  — periodic waveform (sine, triangle, square, sawtooth)
   AudioValueSource     — audio-reactive scalar (RMS, peak, beat detection)
   AdaptiveValueSource  — adapts to external conditions:
       adaptive_time  — interpolates brightness along a 24-hour schedule
       adaptive_scene — derives brightness from a picture source's frame luminance
+  DaylightValueSource  — brightness based on simulated or real-time daylight cycle
 """
 
 from dataclasses import dataclass, field
@@ -21,7 +22,7 @@ class ValueSource:
 
     id: str
     name: str
-    source_type: str  # "static" | "animated" | "audio" | "adaptive_time" | "adaptive_scene"
+    source_type: str  # "static" | "animated" | "audio" | "adaptive_time" | "adaptive_scene" | "daylight"
     created_at: datetime
     updated_at: datetime
     description: Optional[str] = None
@@ -51,6 +52,8 @@ class ValueSource:
             "schedule": None,
             "picture_source_id": None,
             "scene_behavior": None,
+            "use_real_time": None,
+            "latitude": None,
         }
 
     @staticmethod
@@ -121,6 +124,17 @@ class ValueSource:
                 max_value=float(data["max_value"]) if data.get("max_value") is not None else 1.0,
             )
 
+        if source_type == "daylight":
+            return DaylightValueSource(
+                id=sid, name=name, source_type="daylight",
+                created_at=created_at, updated_at=updated_at, description=description, tags=tags,
+                speed=float(data.get("speed") or 1.0),
+                use_real_time=bool(data.get("use_real_time", False)),
+                latitude=float(data.get("latitude") or 50.0),
+                min_value=float(data.get("min_value") or 0.0),
+                max_value=float(data["max_value"]) if data.get("max_value") is not None else 1.0,
+            )
+
         # Default: "static" type
         return StaticValueSource(
             id=sid, name=name, source_type="static",
@@ -221,3 +235,27 @@ class AdaptiveValueSource(ValueSource):
         d["min_value"] = self.min_value
         d["max_value"] = self.max_value
         return d
+
+
+@dataclass
+class DaylightValueSource(ValueSource):
+    """Value source that outputs brightness based on a daylight cycle.
+
+    Uses the same daylight LUT as the CSS daylight stream to derive a
+    scalar brightness from the simulated (or real-time) sky color luminance.
+    """
+
+    speed: float = 1.0              # simulation speed (ignored when use_real_time)
+    use_real_time: bool = False     # use wall clock instead of simulation
+    latitude: float = 50.0          # affects sunrise/sunset in real-time mode
+    min_value: float = 0.0          # output range min
+    max_value: float = 1.0          # output range max
+
+    def to_dict(self) -> dict:
+        d = super().to_dict()
+        d["speed"] = self.speed
+        d["use_real_time"] = self.use_real_time
+        d["latitude"] = self.latitude
+        d["min_value"] = self.min_value
+        d["max_value"] = self.max_value
+        return d