fix(logging): use space-separated timestamps in unified log (1.2.12)

Replace ISO T with YYYY-MM-DD HH:MM:SS so runtime log UI can wrap and display cleanly.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/jiangchang_skill_core/unified_logging.py

@@ -87,7 +87,7 @@ class _SkillContextFilter(logging.Filter):
 _FORMAT = (
     "%(asctime)s | %(levelname)-8s | %(trace_id)s | %(skill_slug)s | %(name)s | %(message)s"
 )
-_DATEFMT = "%Y-%m-%dT%H:%M:%S"
+_DATEFMT = "%Y-%m-%d %H:%M:%S"
 
 
 def _log_level_from_env() -> int: