Refactor enrichment confg updater (#22325)

* enrichment updater and enum

* update_config stubs

* config updaters in enrichments

* update maintainer

* formatting

* simplify enrichment config updates to use single subscriber with topic-based routing

frigate/data_processing/post/api.py

@@ -50,3 +50,16 @@ class PostProcessorApi(ABC):
             None if request was not handled, otherwise return response.
         """
         pass
+
+    def update_config(self, topic: str, payload: Any) -> None:
+        """Handle a config change notification.
+
+        Called for every config update published under ``config/``.
+        Processors should override this to check the topic and act only
+        on changes relevant to them. Default is a no-op.
+
+        Args:
+            topic: The config topic that changed.
+            payload: The updated configuration object.
+        """
+        pass

frigate/data_processing/post/license_plate.py

@@ -12,7 +12,6 @@ from frigate.comms.embeddings_updater import EmbeddingsRequestEnum
 from frigate.comms.event_metadata_updater import EventMetadataPublisher
 from frigate.comms.inter_process import InterProcessRequestor
 from frigate.config import FrigateConfig
-from frigate.config.classification import LicensePlateRecognitionConfig
 from frigate.data_processing.common.license_plate.mixin import (
     WRITE_DEBUG_IMAGES,
     LicensePlateProcessingMixin,
@@ -48,10 +47,15 @@ class LicensePlatePostProcessor(LicensePlateProcessingMixin, PostProcessorApi):
         self.sub_label_publisher = sub_label_publisher
         super().__init__(config, metrics, model_runner)
 
-    def update_config(self, lpr_config: LicensePlateRecognitionConfig) -> None:
+    CONFIG_UPDATE_TOPIC = "config/lpr"
+
+    def update_config(self, topic: str, payload: Any) -> None:
         """Update LPR config at runtime."""
-        self.lpr_config = lpr_config
-        logger.debug("LPR config updated dynamically")
+        if topic != self.CONFIG_UPDATE_TOPIC:
+            return
+
+        self.lpr_config = payload
+        logger.debug("LPR post-processor config updated dynamically")
 
     def process_data(
         self, data: dict[str, Any], data_type: PostProcessDataEnum