chore: migrate omarchy state from ~/.config to ~/.local/state

Move all omarchy runtime state (themes, backgrounds, current theme)
from ~/.config/omarchy/current to ~/.local/state/omarchy/current
to keep the config dir free of generated files. Add mise task for
recreating symlinks and update credential helpers for tea.

script/omarchy-theme-current

@@ -3,7 +3,7 @@
 # omarchy:summary=Show current theme
 # omarchy:examples=omarchy theme current
 
-THEME_NAME_PATH="$HOME/.config/omarchy/current/theme.name"
+THEME_NAME_PATH="$HOME/.local/state/omarchy/current/theme.name"
 
 if [[ -f $THEME_NAME_PATH ]]; then
   cat $THEME_NAME_PATH | sed -E 's/(^|-)([a-z])/\1\u\2/g; s/-/ /g'