Update hub_dashboard_service.py

hub_dashboard_service.py

@@ -457,7 +457,7 @@ class FileBasedLoggerAdapter:
         raw.reverse()  # newest first
         return raw
 
-    def _line_to_entry(self, line: str) -> dict | None:
+    def _line_to_entry(self, line: str) -> Optional[dict]:
         ts_m = self._TS_RE.search(line)
         if not ts_m:
             return None
@@ -478,7 +478,7 @@ class FileBasedLoggerAdapter:
 
     # ── RankerLogger interface ─────────────────────────────────────────────────
 
-    def get_recent(self, n: int = 50, category: str | None = None) -> list:
+    def get_recent(self, n: int = 50, category: Optional[str] = None) -> list:
         entries = []
         for line in self._read_lines(n_tail=max(n * 3, 200)):
             e = self._line_to_entry(line)