feat(logs): Update pruning heuristic to always remove empty logs regardless of age

src/log_registry.py

@@ -222,6 +222,7 @@ class LogRegistry:
   """
         Retrieves a list of sessions that are older than a specific cutoff time 
         and are not marked as whitelisted.
+        Also includes non-whitelisted sessions that are empty (message_count=0 or size_kb=0).
 
         Args:
             cutoff_datetime (datetime): The threshold time for identifying old sessions.
@@ -241,11 +242,19 @@ class LogRegistry:
    else:
     start_time = start_time_raw
    is_whitelisted = session_data.get('whitelisted', False)
-   if start_time is not None and start_time < cutoff_datetime and not is_whitelisted:
-    old_sessions.append({
-      'session_id': session_id,
-      'path': session_data.get('path'),
-      'start_time': start_time_raw
-     })
+   
+   # Heuristic: also include non-whitelisted sessions that have 0 messages or 0 KB size
+   metadata = session_data.get('metadata', {}) or {}
+   message_count = metadata.get('message_count', -1)
+   size_kb = metadata.get('size_kb', -1)
+   is_empty = (message_count == 0 or size_kb == 0)
+   
+   if start_time is not None and not is_whitelisted:
+    if start_time < cutoff_datetime or is_empty:
+     old_sessions.append({
+       'session_id': session_id,
+       'path': session_data.get('path'),
+       'start_time': start_time_raw
+      })
   return old_sessions