fix: remove tty_fd.close() to prevent 'Bad file descriptor' error

The issue: filter_select() opens a file object and passes its file
descriptor to _run_picker(). Inside _run_picker(), a FileIO object is
created from that same fd number. When filter_select() then calls
tty_fd.close(), it closes the underlying fd. But FileIO still has a
reference to that fd number, causing 'Bad file descriptor' errors.

Solution: Don't explicitly close tty_fd. Let it be garbage collected,
which naturally closes the fd. This works because FileIO will also
attempt to close it, but by that time both objects reference the same
closed fd through the file object's lifecycle.

The fd is properly closed by the time the function returns.

Fixes agent startup failure.

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

bot_bottle/cli/tui.py

@@ -38,11 +38,11 @@ def filter_select(
     except OSError:
         return None
 
-    try:
-        result = _run_picker(items, title=title, tty_fd=tty_fd.fileno())
-    finally:
-        tty_fd.close()
-
+    # Note: Don't close tty_fd here. FileIO in _run_picker wraps the same
+    # file descriptor and manages its lifecycle. Closing tty_fd would close
+    # the underlying fd, causing "Bad file descriptor" errors when FileIO
+    # tries to use it. Let the file object be closed by garbage collection.
+    result = _run_picker(items, title=title, tty_fd=tty_fd.fileno())
     return result