fix(tests): handle bold→bright conversion in complex style test

tmux <3.2 normalizes 'bold' to 'bright' in style output.
Added version guard to expect correct output format.

Verification method:
- Created git worktrees for tmux versions 3.0a, 3.1b, 3.2a, 3.3a, 3.4, 3.5
- Examined source code to trace style handling across versions
- Tested directly with tmux commands to verify actual behavior

In tmux ≤3.1, styles are parsed and normalized when stored:
- attributes_fromstring() accepts both "bold" and "bright" as aliases
- attributes_tostring() always outputs "bright" (never "bold")

References:
- tmux-3.0a/attributes.c:32-50 (attributes_fromstring table)
- tmux-3.0a/attributes.c:26-28 (attributes_tostring output)
- tmux-3.0a/options.c:126-127 (OPTIONS_IS_STYLE → style_tostring)
- tmux commit f03b6113 (tmux 3.2 style format change)

Author: tony

tests/test_options.py

@@ -605,7 +605,12 @@ def test_style_option_validation(server: Server) -> None:
         )
         style = session.show_option("status-style")
         assert isinstance(style, str)
-        assert style == "fg=colour240,bg=#525252,bold,underscore"
+        if has_gte_version("3.2"):
+            # tmux 3.2+: literal string output
+            assert style == "fg=colour240,bg=#525252,bold,underscore"
+        else:
+            # tmux <3.2: bold→bright
+            assert style == "fg=colour240,bg=#525252,bright,underscore"
 
         # Test style with variables
         session.set_option("status-style", "fg=#{?pane_in_mode,red,green}")