refactor(config): streamline claude and shell configuration

Remove custom agent definitions that duplicate plugin functionality.
Add Python cache directory configuration for XDG compliance.
Fix Pictures directory ignore pattern in chezmoi.

Signed-off-by: Yihuang Yu <yuyihuang@live.com>

Author: YvanY0

home/.chezmoiignore.tmpl

@@ -43,5 +43,5 @@
 .ssh/config.d/*
 !.ssh/config.d/global
 
-Pictures/*
+Pictures/
 {{- end }}