Add handler for block_actions interactions

These will be interactions from e.g. choosing a template from a static
select menu.

src/templatebot/config.py

@@ -247,10 +247,12 @@ class Config(BaseSettings):
         ),
     )
 
-    interaction_topic: str = Field(
-        "squarebot.interaction",
-        title="interaction Kafka topic",
-        description=("Kafka topic name for `interaction` Slack events"),
+    block_actions_topic: str = Field(
+        "squarebot.block-actions",
+        description=(
+            "Kafka topic name for Slack block actions interaction "
+            "Slack events"
+        ),
     )
 
     model_config = SettingsConfigDict(

src/templatebot/handlers/kafka.py

@@ -7,6 +7,7 @@
 from faststream.security import BaseSecurity
 from rubin.squarebot.models.kafka import (
     SquarebotSlackAppMentionValue,
+    SquarebotSlackBlockActionsValue,
     SquarebotSlackMessageValue,
 )
 from structlog import get_logger
@@ -68,3 +69,20 @@ async def handle_slack_app_mention(
 
     message_service = factory.create_slack_message_service()
     await message_service.handle_app_mention(message)
+
+
+@kafka_router.subscriber(
+    config.block_actions_topic,
+    group_id=f"{config.consumer_group_id}-block-actions",
+)
+async def handle_slack_block_actions(
+    payload: SquarebotSlackBlockActionsValue,
+    context: Annotated[ConsumerContext, Depends(consumer_context_dependency)],
+) -> None:
+    """Handle a Slack block_actions interaction."""
+    logger = context.logger
+
+    logger.debug(
+        "Got Slack block_actions",
+        actions=payload.actions[0].model_dump(mode="json"),
+    )