feat(install): add Starship cloud-module picker to onboarding

install/customize-starship.sh uses fzf --multi (with a y/n fallback when
fzf isn't installed yet) to let the user pick aws/azure/gcloud modules
for the prompt. Toggles the `disabled` flag in xdg/starship.toml in
place, preserving format/symbol/style lines, and appends the [gcloud]
section when absent.

Wired into install-macos.sh and install-linux.sh as an optional step
after oh-my-zsh, defaulting to No so the unattended path stays clean.
Script is re-runnable anytime:  bash install/customize-starship.sh

Author: sleistner

install/customize-starship.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+# Interactive selector for cloud-provider modules in the Starship prompt.
+# Edits xdg/starship.toml in place (which is symlinked into ~/.config/).
+# Safe to re-run: currently-enabled modules are pre-selected.
+#
+# Invoked optionally at the end of install/install-{macos,linux}.sh, or run
+# standalone from the repo root:  bash install/customize-starship.sh
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]:-$0}")" && pwd)"
+CONFIG="$(cd "$SCRIPT_DIR/.." && pwd)/xdg/starship.toml"
+[ -f "$CONFIG" ] || { echo "starship.toml not found at $CONFIG" >&2; exit 1; }
+
+MODULES=(aws azure gcloud)
+
+currently_enabled() {
+  awk '
+    /^\[/ { gsub(/[][]/, "", $0); section=$0; next }
+    section ~ /^(aws|azure|gcloud)$/ && $0 ~ /^disabled[[:space:]]*=[[:space:]]*false/ {
+      print section
+    }
+  ' "$CONFIG"
+}
+
+enabled_before="$(currently_enabled | paste -sd, - || true)"
+
+if command -v fzf >/dev/null 2>&1; then
+  chosen="$(
+    printf '%s\n' "${MODULES[@]}" | fzf \
+      --multi --height='~30%' --reverse \
+      --prompt='Enable cloud modules> ' \
+      --header=$'Tab: toggle · Enter: confirm · currently enabled: '"${enabled_before:-none}" \
+      || true
+  )"
+else
+  echo "fzf not installed — falling back to y/n prompts."
+  chosen=""
+  for m in "${MODULES[@]}"; do
+    default="n"; currently_enabled | grep -qxF "$m" && default="y"
+    read -r -p "Enable $m? [y/n] (current: $default) " reply </dev/tty || reply=""
+    reply="${reply:-$default}"
+    case "$reply" in [Yy]*) chosen+="$m"$'\n' ;; esac
+  done
+fi
+
+toggle_section() {
+  local mod="$1" val="$2" tmp
+  if grep -q "^\[$mod\]" "$CONFIG"; then
+    tmp="$(mktemp)"
+    awk -v section="[$mod]" -v value="$val" '
+      /^\[/ { in_s = ($0 == section) ? 1 : 0 }
+      in_s && /^disabled[[:space:]]*=/ { print "disabled = " value; next }
+      { print }
+    ' "$CONFIG" >"$tmp" && mv "$tmp" "$CONFIG"
+  else
+    printf '\n[%s]\ndisabled = %s\n' "$mod" "$val" >>"$CONFIG"
+  fi
+}
+
+for m in "${MODULES[@]}"; do
+  if printf '%s\n' "$chosen" | grep -qxF "$m"; then
+    toggle_section "$m" false
+  else
+    toggle_section "$m" true
+  fi
+done
+
+echo
+echo "Starship cloud modules now enabled:"
+enabled_now="$(currently_enabled | paste -sd, - || true)"
+echo "  ${enabled_now:-none}"
+if [ "$enabled_before" != "$enabled_now" ]; then
+  echo
+  echo "xdg/starship.toml was modified. Review with: git -C \"$(cd "$SCRIPT_DIR/.." && pwd)\" diff xdg/starship.toml"
+fi

install/install-linux.sh

@@ -73,6 +73,14 @@ run_setup_symlinks
 # 4. oh-my-zsh + zsh-autosuggestions
 install_oh_my_zsh
 
+# 5. Optional: pick cloud-provider modules for the Starship prompt.
+step "Starship prompt customization (optional)"
+if prompt_yes_no "Pick which cloud modules (aws/azure/gcloud) show in the prompt?" N; then
+  bash "$DOTFILES_DIR/install/customize-starship.sh"
+else
+  ok "skipped (edit xdg/starship.toml or re-run install/customize-starship.sh anytime)"
+fi
+
 cat <<EOF
 
 ${c_green}Core automated steps complete.${c_reset}

install/install-macos.sh

@@ -79,6 +79,14 @@ ok "Brewfile installed"
 # 6. oh-my-zsh + zsh-autosuggestions
 install_oh_my_zsh
 
+# 7. Optional: pick cloud-provider modules for the Starship prompt.
+step "Starship prompt customization (optional)"
+if prompt_yes_no "Pick which cloud modules (aws/azure/gcloud) show in the prompt?" N; then
+  bash "$DOTFILES_DIR/install/customize-starship.sh"
+else
+  ok "skipped (edit xdg/starship.toml or re-run install/customize-starship.sh anytime)"
+fi
+
 cat <<EOF
 
 ${c_green}All automated steps complete.${c_reset}