feat(install): set wallhaven 2133ly as default wallpaper

- lib/wallpaper.sh: downloads the default wallpaper at install time
  (tries .jpg then .png against the wallhaven CDN path) into
  ~/.config/hypr/wallpapers/default.<ext> and writes hyprpaper.conf
  pointing at it
- Override the source with WALLPAPER_URL=<direct-image-url> or just the
  URL stem with WALLPAPER_URL_BASE
- Existing hyprpaper.conf is backed up to .pre-install.<timestamp>
  unless it's already ours (marker comment)
- files/hypr/autostart.conf: exec-once = hyprpaper
- install.sh: wire setup_wallpaper into do_dotfiles_and_config

Tried to fetch from this sandbox to verify the extension but wallhaven
blocks datacenter IPs (403); the installer probes .jpg first then .png
when it actually runs on a residential network.

install/README.md

@@ -88,6 +88,12 @@ top-right anchored, JetBrainsMono Nerd Font, per-urgency border colors
 a rofi-driven menu with Lock / Suspend / Logout / Reboot / Shutdown.
 Bound to **Super + Shift + E** in Hyprland and to the Waybar power button.
 
+**Wallpaper:** downloads
+[wallhaven.cc/w/2133ly](https://wallhaven.cc/w/2133ly) to
+`~/.config/hypr/wallpapers/default.jpg` and writes `hyprpaper.conf` pointing
+at it. Override with `WALLPAPER_URL=<direct-image-url>` before running the
+installer (any pre-existing `hyprpaper.conf` is backed up first).
+
 **Services enabled:** `sddm`, `NetworkManager`, `bluetooth`; user-level
 `pipewire`, `pipewire-pulse`, `wireplumber`.
 

install/files/hypr/autostart.conf

@@ -1,7 +1,8 @@
 # Polkit agent for authentication dialogs.
 exec-once = /usr/lib/polkit-gnome/polkit-gnome-authentication-agent-1
 
-# Top bar + notifications + idle.
+# Wallpaper, top bar, notifications, idle.
+exec-once = hyprpaper
 exec-once = waybar
 exec-once = mako
 exec-once = hypridle

install/install.sh

@@ -20,6 +20,7 @@ source "$SCRIPT_DIR/lib/common.sh"
 source "$SCRIPT_DIR/lib/packages.sh"
 source "$SCRIPT_DIR/lib/dotfiles.sh"
 source "$SCRIPT_DIR/lib/hyprland.sh"
+source "$SCRIPT_DIR/lib/wallpaper.sh"
 source "$SCRIPT_DIR/lib/services.sh"
 
 usage() {
@@ -55,6 +56,7 @@ do_packages() {
 do_dotfiles_and_config() {
   link_dotfiles
   link_hyprland_config
+  setup_wallpaper
   install_tpm
   install_nvm
   set_zsh_as_shell

install/lib/wallpaper.sh

@@ -0,0 +1,98 @@
+#!/bin/bash
+# Download the default wallpaper and write the hyprpaper config.
+# Override the source URL with $WALLPAPER_URL (must be a direct image link).
+
+# Default: https://wallhaven.cc/w/2133ly  (direct CDN path)
+DEFAULT_WALLPAPER_BASE="${WALLPAPER_URL_BASE:-https://w.wallhaven.cc/full/21/wallhaven-2133ly}"
+
+WALLPAPER_DIR="$HOME/.config/hypr/wallpapers"
+WALLPAPER_NAME="default"
+
+download_wallpaper() {
+  mkdir -p "$WALLPAPER_DIR"
+
+  # If the user passed a fully-qualified URL, honor it directly.
+  if [[ -n ${WALLPAPER_URL:-} ]]; then
+    local ext="${WALLPAPER_URL##*.}"
+    [[ $ext =~ ^(jpg|jpeg|png|webp)$ ]] || ext="jpg"
+    local target="$WALLPAPER_DIR/$WALLPAPER_NAME.$ext"
+    if [[ -s $target ]]; then
+      info "Wallpaper already downloaded: $target"
+      WALLPAPER_PATH="$target"
+      return
+    fi
+    info "Downloading wallpaper from $WALLPAPER_URL"
+    curl -fsSL --retry 3 -o "$target" "$WALLPAPER_URL" || {
+      warn "Wallpaper download failed; hyprpaper will fall back to no wallpaper."
+      WALLPAPER_PATH=""
+      return
+    }
+    WALLPAPER_PATH="$target"
+    return
+  fi
+
+  # Default path: try .jpg then .png against the wallhaven pattern.
+  local ext target
+  for ext in jpg png; do
+    target="$WALLPAPER_DIR/$WALLPAPER_NAME.$ext"
+    if [[ -s $target ]]; then
+      info "Wallpaper already downloaded: $target"
+      WALLPAPER_PATH="$target"
+      return
+    fi
+  done
+
+  for ext in jpg png; do
+    local url="$DEFAULT_WALLPAPER_BASE.$ext"
+    target="$WALLPAPER_DIR/$WALLPAPER_NAME.$ext"
+    info "Trying wallpaper: $url"
+    if curl -fsSL --retry 2 -o "$target" "$url"; then
+      WALLPAPER_PATH="$target"
+      return
+    fi
+    rm -f "$target"
+  done
+
+  warn "Could not download default wallpaper from $DEFAULT_WALLPAPER_BASE.(jpg|png)."
+  warn "Set WALLPAPER_URL=<direct-image-url> and re-run install/install.sh --dotfiles-only"
+  WALLPAPER_PATH=""
+}
+
+write_hyprpaper_config() {
+  local conf="$HOME/.config/hypr/hyprpaper.conf"
+  mkdir -p "$(dirname "$conf")"
+
+  # Back up any pre-existing non-empty config (unless it's already ours).
+  if [[ -s $conf ]] && ! grep -q '^# Generated by dotfiles install/lib/wallpaper.sh' "$conf"; then
+    local backup="$conf.pre-install.$(date +%s)"
+    cp "$conf" "$backup"
+    info "Backed up existing hyprpaper.conf -> $backup"
+  fi
+
+  if [[ -z ${WALLPAPER_PATH:-} ]]; then
+    # No image — write a no-op config so hyprpaper starts cleanly.
+    cat >"$conf" <<'EOF'
+# Generated by dotfiles install/lib/wallpaper.sh
+# No wallpaper configured. Set WALLPAPER_URL and re-run install.sh, or
+# add `preload = <path>` and `wallpaper = ,<path>` lines below.
+splash = false
+ipc = on
+EOF
+    info "Wrote stub hyprpaper.conf (no wallpaper)"
+    return
+  fi
+
+  cat >"$conf" <<EOF
+# Generated by dotfiles install/lib/wallpaper.sh
+preload = $WALLPAPER_PATH
+wallpaper = ,$WALLPAPER_PATH
+splash = false
+ipc = on
+EOF
+  info "Wrote hyprpaper.conf -> $WALLPAPER_PATH"
+}
+
+setup_wallpaper() {
+  download_wallpaper
+  write_hyprpaper_config
+}