feat: add TUI-safe logging mode that disables RichHandler

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/utils/logging.py

@@ -77,6 +77,21 @@ def setup_logging(
     )
 
 
+def setup_logging_for_tui() -> None:
+    """Reconfigure logging for Textual TUI mode.
+
+    Removes the RichHandler (which writes to stdout and corrupts the TUI)
+    while preserving any file handlers. Call this from the Textual App's
+    on_mount() before any agent work begins.
+    """
+    from rich.logging import RichHandler
+
+    root_logger = logging.getLogger()
+    root_logger.handlers = [
+        h for h in root_logger.handlers if not isinstance(h, RichHandler)
+    ]
+
+
 def get_logger(name: str) -> structlog.stdlib.BoundLogger:
     """Get a named structlog logger.