feat(core): migrate system state to unified declarative JSON

- Consolidate all configuration toggles (suspend, idle, waybar, etc.) into ~/.config/home-manager/state.json
- Introduce nomarchy.toggles and nomarchy.hyprland options in Nix
- Inject toggle states into all bin/ scripts via environment variables
- Update toggle scripts to mutate JSON and trigger background rebuilds
- Add a migration script to transition legacy flag files to the new format

bin/nomarchy-theme-bg-next

@@ -4,10 +4,11 @@
 # Declarative + Hybrid (instant swww) for Nomarchy NixOS.
 
 STATE_DIR="$HOME/.config/home-manager"
-THEME_STATE_FILE="$STATE_DIR/theme-state.nix"
-WALLPAPER_STATE_FILE="$STATE_DIR/wallpaper-state.nix"
+STATE_FILE="$STATE_DIR/state.json"
+mkdir -p "$STATE_DIR"
+[[ ! -f $STATE_FILE ]] && echo "{}" > "$STATE_FILE"
 
-THEME_NAME=$(cat "$THEME_STATE_FILE" 2>/dev/null || echo "nord")
+THEME_NAME=$(jq -r '.theme // "nord"' "$STATE_FILE")
 
 if [ -d "/etc/nixos/nomarchy/themes" ]; then
   THEMES_DIR="/etc/nixos/nomarchy/themes"
@@ -32,7 +33,7 @@ if (( TOTAL == 0 )); then
     exit 1
 fi
 
-CURRENT_BG=$(cat "$WALLPAPER_STATE_FILE" 2>/dev/null)
+CURRENT_BG=$(jq -r '.wallpaper' "$STATE_FILE")
 INDEX=-1
 for i in "${!BACKGROUNDS[@]}"; do
     if [[ "$BG_DIR/${BACKGROUNDS[$i]}" == "$CURRENT_BG" ]]; then
@@ -44,7 +45,8 @@ done
 NEXT_INDEX=$(((INDEX + 1) % TOTAL))
 NEW_BG="$BG_DIR/${BACKGROUNDS[$NEXT_INDEX]}"
 
-echo "$NEW_BG" > "$WALLPAPER_STATE_FILE"
+TMP_JSON=$(mktemp)
+jq ".wallpaper = \"$NEW_BG\"" "$STATE_FILE" > "$TMP_JSON" && mv "$TMP_JSON" "$STATE_FILE"
 
 # Instant feedback via swww
 if pgrep -x swww-daemon >/dev/null; then