refactor: replace type-dispatch if/elif chains with registry patterns and handler maps

Backend: add registry dicts (_CONDITION_MAP, _VALUE_SOURCE_MAP, _PICTURE_SOURCE_MAP)
and per-subclass from_dict() methods to eliminate ~300 lines of if/elif in factory
functions. Convert automation engine dispatch (condition eval, match_mode, match_type,
deactivation_mode) to dict-based lookup.

Frontend: extract CSS_CARD_RENDERERS, CSS_SECTION_MAP, CSS_TYPE_SETUP,
CONDITION_PILL_RENDERERS, and PICTURE_SOURCE_CARD_RENDERERS handler maps to replace
scattered type-check chains in color-strips.ts, automations.ts, and streams.ts.

server/src/wled_controller/storage/automation.py

@@ -2,7 +2,7 @@
 
 from dataclasses import dataclass, field
 from datetime import datetime, timezone
-from typing import List, Optional
+from typing import Dict, List, Optional, Type
 
 
 @dataclass
@@ -16,25 +16,12 @@ class Condition:
 
     @classmethod
     def from_dict(cls, data: dict) -> "Condition":
-        """Factory: dispatch to the correct subclass."""
+        """Factory: dispatch to the correct subclass via registry."""
         ct = data.get("condition_type", "")
-        if ct == "always":
-            return AlwaysCondition.from_dict(data)
-        if ct == "application":
-            return ApplicationCondition.from_dict(data)
-        if ct == "time_of_day":
-            return TimeOfDayCondition.from_dict(data)
-        if ct == "system_idle":
-            return SystemIdleCondition.from_dict(data)
-        if ct == "display_state":
-            return DisplayStateCondition.from_dict(data)
-        if ct == "mqtt":
-            return MQTTCondition.from_dict(data)
-        if ct == "webhook":
-            return WebhookCondition.from_dict(data)
-        if ct == "startup":
-            return StartupCondition.from_dict(data)
-        raise ValueError(f"Unknown condition type: {ct}")
+        subcls = _CONDITION_MAP.get(ct)
+        if subcls is None:
+            raise ValueError(f"Unknown condition type: {ct}")
+        return subcls.from_dict(data)
 
 
 @dataclass
@@ -190,6 +177,18 @@ class StartupCondition(Condition):
         return cls()
 
 
+_CONDITION_MAP: Dict[str, Type[Condition]] = {
+    "always": AlwaysCondition,
+    "application": ApplicationCondition,
+    "time_of_day": TimeOfDayCondition,
+    "system_idle": SystemIdleCondition,
+    "display_state": DisplayStateCondition,
+    "mqtt": MQTTCondition,
+    "webhook": WebhookCondition,
+    "startup": StartupCondition,
+}
+
+
 @dataclass
 class Automation:
     """Automation that activates a scene preset based on conditions."""