Add seasonal palettes and selection prompts

- Implement dynamic/static season support in shared PS1

- Add season selection prompts to Linux and macOS installers

dotfiles/ps1/ps1.sh

@@ -37,6 +37,58 @@ _ps1_has_nf() {
   return 1
 }
 
+# Season selection (dynamic or static)
+#   PS1_SEASON_MODE=dynamic|static
+#   PS1_SEASON= winter|spring|summer|autumn
+# Also reads config from /etc/ps1-season or ~/.config/ps1/season
+_ps1_season_config() {
+  local cfg=""
+  if [[ -r /etc/ps1-season ]]; then
+    cfg="/etc/ps1-season"
+  elif [[ -r "$HOME/.config/ps1/season" ]]; then
+    cfg="$HOME/.config/ps1/season"
+  fi
+
+  if [[ -n "$cfg" ]]; then
+    while IFS='=' read -r k v; do
+      k="${k//[[:space:]]/}"
+      v="${v//[[:space:]]/}"
+      case "$k" in
+        PS1_SEASON_MODE) export PS1_SEASON_MODE="$v" ;;
+        PS1_SEASON) export PS1_SEASON="$v" ;;
+      esac
+    done < "$cfg"
+  fi
+}
+
+_ps1_season_dynamic() {
+  local mm dd m d
+  mm=$(TZ=Europe/Oslo date +%m); dd=$(TZ=Europe/Oslo date +%d)
+  m=$((10#$mm)); d=$((10#$dd))
+
+  if (( m >= 3 && m <= 5 )); then
+    echo "spring"
+  elif (( m >= 6 && m <= 8 )); then
+    echo "summer"
+  elif (( m == 9 || m == 10 || (m == 11 && d < 15) )); then
+    echo "autumn"
+  else
+    echo "winter"
+  fi
+}
+
+_ps1_season() {
+  _ps1_season_config
+  local mode="${PS1_SEASON_MODE:-dynamic}"
+  local season="${PS1_SEASON:-}"
+
+  if [[ "$mode" == "static" && -n "$season" ]]; then
+    echo "$season"
+  else
+    _ps1_season_dynamic
+  fi
+}
+
 # Time-based emoji (Europe/Oslo)
 _ps1_symbol() {
   local hh mm h m
@@ -73,22 +125,48 @@ __PS1_SYM=""
 __PS1_PATH=""
 __PS1_STATUS=0
 __PS1_USE_NF=0
+__PS1_SEASON="winter"
 
 _ps1_set_prompt() {
   local RST="\[\e[0m\]"
 
-  # Two-zone palette
-  # Zone 1: gray-blue pastel (date/time/user)
-  local Z1_BG="\[\e[48;5;61m\]"
-  local Z1_FG="\[\e[38;5;255m\]"
-
-  # Zone 2: turquoise / cool green (host/path)
-  local Z2_BG="\[\e[48;5;37m\]"
-  local Z2_FG="\[\e[38;5;255m\]"
-  local PATH_FG="\[\e[38;5;194m\]"
-
-  # Frame
-  local FRAME="\[\e[38;5;60m\]"
+  # Seasonal palettes (Z1 is darker than Z2)
+  local Z1_BG Z1_FG Z2_BG Z2_FG PATH_FG FRAME
+  case "$__PS1_SEASON" in
+    spring)
+      Z1_BG="\[\e[48;5;71m\]"
+      Z1_FG="\[\e[38;5;255m\]"
+      Z2_BG="\[\e[48;5;120m\]"
+      Z2_FG="\[\e[38;5;255m\]"
+      PATH_FG="\[\e[38;5;193m\]"
+      FRAME="\[\e[38;5;65m\]"
+      ;;
+    summer)
+      Z1_BG="\[\e[48;5;142m\]"
+      Z1_FG="\[\e[38;5;255m\]"
+      Z2_BG="\[\e[48;5;214m\]"
+      Z2_FG="\[\e[38;5;0m\]"
+      PATH_FG="\[\e[38;5;223m\]"
+      FRAME="\[\e[38;5;130m\]"
+      ;;
+    autumn)
+      Z1_BG="\[\e[48;5;95m\]"
+      Z1_FG="\[\e[38;5;255m\]"
+      Z2_BG="\[\e[48;5;173m\]"
+      Z2_FG="\[\e[38;5;255m\]"
+      PATH_FG="\[\e[38;5;223m\]"
+      FRAME="\[\e[38;5;95m\]"
+      ;;
+    *)
+      # winter (default)
+      Z1_BG="\[\e[48;5;61m\]"
+      Z1_FG="\[\e[38;5;255m\]"
+      Z2_BG="\[\e[48;5;37m\]"
+      Z2_FG="\[\e[38;5;255m\]"
+      PATH_FG="\[\e[38;5;194m\]"
+      FRAME="\[\e[38;5;60m\]"
+      ;;
+  esac
 
   # Status colors
   local OK="\[\e[38;5;76m\]"
@@ -122,6 +200,7 @@ _ps1_update() {
   __PS1_STATUS=$?
   __PS1_SYM="$(_ps1_symbol)"
   __PS1_PATH="$(_ps1_path)"
+  __PS1_SEASON="$(_ps1_season)"
   if _ps1_has_nf; then __PS1_USE_NF=1; else __PS1_USE_NF=0; fi
   _ps1_set_prompt
 }