diff --git a/.config/zsh/rc.d/05-prompt.zsh b/.config/zsh/rc.d/05-prompt.zsh
index 8fd835b..6e9e41d 100644
--- a/.config/zsh/rc.d/05-prompt.zsh
+++ b/.config/zsh/rc.d/05-prompt.zsh
@@ -1,32 +1,15 @@
-# Prompt. Sourced by the stub BEFORE oh-my-zsh, and that placement is the whole
-# point of the file.
+# Theme selection. Sourced by the stub BEFORE oh-my-zsh, and that placement is
+# the point of the file.
 #
-# oh-my-zsh loads the theme while it is being sourced, and powerlevel10k reads
-# its POWERLEVEL9K_* settings when it loads. Anything set afterwards is simply
-# ignored - the first attempt put ZSH_THEME in the role file, which is sourced
-# after oh-my-zsh, and the result was a shell with no powerlevel10k at all
-# while still reporting the right value in ZSH_THEME.
+# oh-my-zsh loads the theme while it is being sourced, so ZSH_THEME set
+# afterwards is ignored - the first attempt put it in the role file and produced
+# a shell reporting the right value while running without powerlevel10k at all.
+#
+# The role COLOUR is deliberately not here. ~/.p10k.zsh sets
+# POWERLEVEL9K_CONTEXT_BACKGROUND itself and is sourced later, so a colour set
+# here is overwritten before the first prompt is ever drawn. It lives in the
+# role files, which come after.
 
-# Only claim the theme if it is actually installed, otherwise oh-my-zsh falls
-# back to robbyrussell with a complaint.
 if [[ -d "${ZSH_CUSTOM:-$ZSH/custom}/themes/powerlevel10k" ]]; then
   ZSH_THEME="powerlevel10k/powerlevel10k"
 fi
-
-# Colour by role. Not decoration: shron carries mail, web and cloud, and a
-# glance at the prompt should be enough to know which machine the next command
-# is about to hit. Same segments everywhere so nothing else has to be relearned.
-case "$ROLE" in
-  server)
-    typeset -g POWERLEVEL9K_CONTEXT_BACKGROUND=red
-    # Show the host even locally. Noise on a desktop, the one thing worth
-    # always seeing here.
-    typeset -g POWERLEVEL9K_ALWAYS_SHOW_CONTEXT=true
-    ;;
-  mobile)
-    typeset -g POWERLEVEL9K_CONTEXT_BACKGROUND=green
-    ;;
-  *)
-    typeset -g POWERLEVEL9K_CONTEXT_BACKGROUND=blue
-    ;;
-esac
diff --git a/.config/zsh/rc.d/10-aliases.zsh b/.config/zsh/rc.d/10-aliases.zsh
index ba7922d..1c1a628 100644
--- a/.config/zsh/rc.d/10-aliases.zsh
+++ b/.config/zsh/rc.d/10-aliases.zsh
@@ -5,6 +5,18 @@
 # machine where lsd is not installed - the Mac, for one - and breaking ls is
 # the sort of thing that makes a shared dotfile repository feel like a mistake.
 
+# The dotfiles repository itself. A bare repo in ~/.cfg with $HOME as its work
+# tree, so "config" behaves like git for the configuration and the real git
+# stays out of the way in ordinary projects.
+#
+#   config status          what has drifted
+#   config add .zshrc      track a change
+#   config commit -m ...   and push as usual
+#
+# status.showUntrackedFiles=no is set in the repo, otherwise every file in
+# $HOME would show up as untracked.
+[[ -d "$HOME/.cfg" ]] && alias config='/usr/bin/git --git-dir=$HOME/.cfg/ --work-tree=$HOME'
+
 alias vi="nvim"
 alias ducks="du -cksh * | sort -rn | head"
 
diff --git a/.config/zsh/rc.d/50-desktop.zsh b/.config/zsh/rc.d/50-desktop.zsh
index 4753069..fc26543 100644
--- a/.config/zsh/rc.d/50-desktop.zsh
+++ b/.config/zsh/rc.d/50-desktop.zsh
@@ -38,3 +38,9 @@ for _d in "$HOME/.cargo/bin" "$HOME/.lmstudio/bin"; do
 done
 unset _d
 export PATH
+
+# Role colour, set here rather than in 05-prompt.zsh because ~/.p10k.zsh
+# assigns POWERLEVEL9K_CONTEXT_BACKGROUND itself and is sourced in 30-path.zsh.
+# Anything set before that is silently replaced. Not decoration: shron carries
+# mail, web and cloud, and a glance should say which machine this is.
+typeset -g POWERLEVEL9K_CONTEXT_BACKGROUND=blue
diff --git a/.config/zsh/rc.d/50-mobile.zsh b/.config/zsh/rc.d/50-mobile.zsh
index 8eb842a..e26fe93 100644
--- a/.config/zsh/rc.d/50-mobile.zsh
+++ b/.config/zsh/rc.d/50-mobile.zsh
@@ -14,3 +14,9 @@ for _b in /opt/homebrew /usr/local; do
   fi
 done
 unset _b
+
+# Role colour, set here rather than in 05-prompt.zsh because ~/.p10k.zsh
+# assigns POWERLEVEL9K_CONTEXT_BACKGROUND itself and is sourced in 30-path.zsh.
+# Anything set before that is silently replaced. Not decoration: shron carries
+# mail, web and cloud, and a glance should say which machine this is.
+typeset -g POWERLEVEL9K_CONTEXT_BACKGROUND=green
diff --git a/.config/zsh/rc.d/50-server.zsh b/.config/zsh/rc.d/50-server.zsh
index 63ae574..dba9dd0 100644
--- a/.config/zsh/rc.d/50-server.zsh
+++ b/.config/zsh/rc.d/50-server.zsh
@@ -4,3 +4,12 @@
 # out of the way; anything that assumes a graphical session belongs in
 # 50-desktop.zsh.
 
+# Role colour, set here rather than in 05-prompt.zsh because ~/.p10k.zsh
+# assigns POWERLEVEL9K_CONTEXT_BACKGROUND itself and is sourced in 30-path.zsh.
+# Anything set before that is silently replaced. Not decoration: shron carries
+# mail, web and cloud, and a glance should say which machine this is.
+typeset -g POWERLEVEL9K_CONTEXT_BACKGROUND=red
+# Show the host even in a local shell. Noise on a desktop; here it is the one
+# thing worth always having in view.
+typeset -g POWERLEVEL9K_ALWAYS_SHOW_CONTEXT=true
+