feat: system_metrics value source type

New value source that monitors host hardware via psutil/pynvml:
cpu_load, cpu_temp, gpu_load, gpu_temp, ram_usage, disk_usage,
network_rx, network_tx, battery_level, fan_speed.

Each metric normalizes to 0.0-1.0 with configurable ranges, poll
interval, EMA smoothing, and sensor_label for multi-sensor systems.
Conditional editor fields show/hide based on selected metric.

Also fixes: WS test crash when raw_value streams lack _min_ha attr,
toast timer overlap on rapid calls, SW cache bump to v34.

server/src/wled_controller/api/routes/value_sources.py

@@ -25,6 +25,7 @@ from wled_controller.api.schemas.value_sources import (
     HAEntityValueSourceResponse,
     StaticColorValueSourceResponse,
     StaticValueSourceResponse,
+    SystemMetricsValueSourceResponse,
     ValueSourceCreate,
     ValueSourceListResponse,
     ValueSourceResponse,
@@ -42,6 +43,7 @@ from wled_controller.storage.value_source import (
     HAEntityValueSource,
     StaticColorValueSource,
     StaticValueSource,
+    SystemMetricsValueSource,
     ValueSource,
 )
 from wled_controller.storage.value_source_store import ValueSourceStore
@@ -171,6 +173,22 @@ _RESPONSE_MAP = {
         led_start=s.led_start,
         led_end=s.led_end,
     ),
+    SystemMetricsValueSource: lambda s: SystemMetricsValueSourceResponse(
+        id=s.id,
+        name=s.name,
+        description=s.description,
+        tags=s.tags,
+        created_at=s.created_at,
+        updated_at=s.updated_at,
+        metric=s.metric,
+        min_value=s.min_value,
+        max_value=s.max_value,
+        max_rate=s.max_rate,
+        disk_path=s.disk_path,
+        sensor_label=s.sensor_label,
+        poll_interval=s.poll_interval,
+        smoothing=s.smoothing,
+    ),
 }
 
 
@@ -403,7 +421,8 @@ async def test_value_source_ws(
                 raw = stream.get_raw_value()
                 if raw is not None:
                     msg["raw_value"] = round(raw, 4)
-                    msg["raw_range"] = [stream._min_ha, stream._max_ha]
+                    if hasattr(stream, "_min_ha"):
+                        msg["raw_range"] = [stream._min_ha, stream._max_ha]
             await websocket.send_json(msg)
             await asyncio.sleep(0.05)
     except WebSocketDisconnect:

server/src/wled_controller/api/schemas/value_sources.py

@@ -124,6 +124,19 @@ class CSSExtractValueSourceResponse(_ValueSourceResponseBase):
     led_end: int = Field(description="End of LED range (-1 = whole strip)")
 
 
+class SystemMetricsValueSourceResponse(_ValueSourceResponseBase):
+    source_type: Literal["system_metrics"] = "system_metrics"
+    return_type: Literal["float"] = "float"
+    metric: str = Field(description="System metric to monitor")
+    min_value: float = Field(description="Min value for range-based metrics")
+    max_value: float = Field(description="Max value for range-based metrics")
+    max_rate: float = Field(description="Max rate in bytes/sec for network metrics")
+    disk_path: str = Field(description="Disk path for disk_usage metric")
+    sensor_label: str = Field(description="Sensor label for cpu_temp/fan_speed")
+    poll_interval: float = Field(description="Seconds between reads")
+    smoothing: float = Field(description="EMA smoothing factor (0.0-1.0)")
+
+
 ValueSourceResponse = Annotated[
     Union[
         Annotated[StaticValueSourceResponse, Tag("static")],
@@ -138,6 +151,7 @@ ValueSourceResponse = Annotated[
         Annotated[HAEntityValueSourceResponse, Tag("ha_entity")],
         Annotated[GradientMapValueSourceResponse, Tag("gradient_map")],
         Annotated[CSSExtractValueSourceResponse, Tag("css_extract")],
+        Annotated[SystemMetricsValueSourceResponse, Tag("system_metrics")],
     ],
     Discriminator("source_type"),
 ]
@@ -252,6 +266,18 @@ class CSSExtractValueSourceCreate(_ValueSourceCreateBase):
     led_end: int = Field(-1, description="End of LED range (-1 = whole strip)")
 
 
+class SystemMetricsValueSourceCreate(_ValueSourceCreateBase):
+    source_type: Literal["system_metrics"] = "system_metrics"
+    metric: str = Field("cpu_load", description="System metric to monitor")
+    min_value: float = Field(0.0, description="Min value for normalization")
+    max_value: float = Field(100.0, description="Max value for normalization")
+    max_rate: float = Field(125_000_000.0, description="Max rate bytes/sec for network")
+    disk_path: str = Field("", description="Disk path for disk_usage")
+    sensor_label: str = Field("", description="Sensor label for cpu_temp/fan_speed")
+    poll_interval: float = Field(1.0, description="Poll interval in seconds", ge=0.1, le=60.0)
+    smoothing: float = Field(0.0, description="EMA smoothing (0.0-1.0)", ge=0.0, le=1.0)
+
+
 ValueSourceCreate = Annotated[
     Union[
         Annotated[StaticValueSourceCreate, Tag("static")],
@@ -266,6 +292,7 @@ ValueSourceCreate = Annotated[
         Annotated[HAEntityValueSourceCreate, Tag("ha_entity")],
         Annotated[GradientMapValueSourceCreate, Tag("gradient_map")],
         Annotated[CSSExtractValueSourceCreate, Tag("css_extract")],
+        Annotated[SystemMetricsValueSourceCreate, Tag("system_metrics")],
     ],
     Discriminator("source_type"),
 ]
@@ -374,6 +401,18 @@ class CSSExtractValueSourceUpdate(_ValueSourceUpdateBase):
     led_end: Optional[int] = Field(None, description="LED range end")
 
 
+class SystemMetricsValueSourceUpdate(_ValueSourceUpdateBase):
+    source_type: Literal["system_metrics"] = "system_metrics"
+    metric: Optional[str] = Field(None, description="System metric")
+    min_value: Optional[float] = Field(None, description="Min value")
+    max_value: Optional[float] = Field(None, description="Max value")
+    max_rate: Optional[float] = Field(None, description="Max rate bytes/sec")
+    disk_path: Optional[str] = Field(None, description="Disk path")
+    sensor_label: Optional[str] = Field(None, description="Sensor label")
+    poll_interval: Optional[float] = Field(None, description="Poll interval", ge=0.1, le=60.0)
+    smoothing: Optional[float] = Field(None, description="EMA smoothing", ge=0.0, le=1.0)
+
+
 ValueSourceUpdate = Annotated[
     Union[
         Annotated[StaticValueSourceUpdate, Tag("static")],
@@ -388,6 +427,7 @@ ValueSourceUpdate = Annotated[
         Annotated[HAEntityValueSourceUpdate, Tag("ha_entity")],
         Annotated[GradientMapValueSourceUpdate, Tag("gradient_map")],
         Annotated[CSSExtractValueSourceUpdate, Tag("css_extract")],
+        Annotated[SystemMetricsValueSourceUpdate, Tag("system_metrics")],
     ],
     Discriminator("source_type"),
 ]