chore: add new handler in logging config

Not used yet, will be in the future.

.logging_config.yaml

@@ -7,17 +7,16 @@ custom_levels:
 formatters:
   # Console output
   colored:
-    (): 'colorlog.ColoredFormatter'
-    format: '{log_color}{asctime} | {levelname:11} | {name:70} | {message}'
-    style: '{'
-    datefmt: '%H:%M:%S'
+    (): "colorlog.ColoredFormatter"
+    format: "{log_color}{asctime} | {levelname:11} | {name:70} | {message}"
+    style: "{"
+    datefmt: "%H:%M:%S"
 
   # User-facing UI (structured JSON)
   json_experiment:
-    (): 'pythonjsonlogger.jsonlogger.JsonFormatter'
-    format: '{asctime} {name} {levelname} {message}'
-    style: '{'
-
+    (): "pythonjsonlogger.jsonlogger.JsonFormatter"
+    format: "{asctime} {name} {levelname} {message}"
+    style: "{"
 
 handlers:
   console:
@@ -25,6 +24,11 @@ handlers:
     level: DEBUG
     formatter: colored
     stream: ext://sys.stdout
+  ui:
+    class: zmq.log.handlers.PUBHandler
+    level: DEBUG
+    formatter: json_experiment
+    interface_or_socket: "PLACEHOLDER"
 
 # Level of external libraries
 root:
@@ -32,10 +36,6 @@ root:
   handlers: [console]
 
 loggers:
-  experiment:
-    level: OBSERVATION
-    handlers: [console]  # TODO: custom handler for user-facing logs (ticket about UI logs)
-    propagate: no
   control_backend:
     level: INFO
-
+    handlers: [ui]