fix: guard LogInterceptor.flush() against OSError on Windows no-console setups (fixes #13554)

On Windows, when ComfyUI is launched without an attached console (e.g.
from a desktop shortcut or detached process), sys.__stdout__ may point
to an invalid console handle. Calling flush() on such a handle raises
OSError: [Errno 22] Invalid argument, which propagates up through any
code that calls print() and crashes every prompt execution.

Wrap super().flush() in LogInterceptor.flush() with the same
try/except (OSError, ValueError): pass pattern that is already used
elsewhere in the codebase for exactly this scenario. A failed flush on
a broken console handle just means the line isn't force-drained to that
console; content still reaches log_file and the in-memory log buffers.

Co-Authored-By: Octopus <liyuan851277048@icloud.com>

app/logger.py

@@ -32,7 +32,10 @@ class LogInterceptor(io.TextIOWrapper):
         super().write(data)
 
     def flush(self):
-        super().flush()
+        try:
+            super().flush()
+        except (OSError, ValueError):
+            pass
         for cb in self._flush_callbacks:
             cb(self._logs_since_flush)
             self._logs_since_flush = []