refactor: remove embedded wallpaper from binary (v0.6.2)

Wallpaper is installed by moonarch to /usr/share/moonarch/wallpaper.jpg.
Embedding a 374K JPEG in the binary was redundant. Without a wallpaper
file, GTK background color (Catppuccin Mocha base) shows through.

src/config.rs

@@ -6,7 +6,6 @@ use std::fs;
 use std::path::{Path, PathBuf};
 
 const MOONARCH_WALLPAPER: &str = "/usr/share/moonarch/wallpaper.jpg";
-const GRESOURCE_PREFIX: &str = "/dev/moonarch/moonlock";
 
 fn default_config_paths() -> Vec<PathBuf> {
     let mut paths = vec![PathBuf::from("/etc/moonlock/moonlock.toml")];
@@ -64,17 +63,17 @@ pub fn load_config(config_paths: Option<&[PathBuf]>) -> Config {
     merged
 }
 
-pub fn resolve_background_path(config: &Config) -> PathBuf {
+pub fn resolve_background_path(config: &Config) -> Option<PathBuf> {
     resolve_background_path_with(config, Path::new(MOONARCH_WALLPAPER))
 }
 
-pub fn resolve_background_path_with(config: &Config, moonarch_wallpaper: &Path) -> PathBuf {
+pub fn resolve_background_path_with(config: &Config, moonarch_wallpaper: &Path) -> Option<PathBuf> {
     if let Some(ref bg) = config.background_path {
         let path = PathBuf::from(bg);
-        if path.is_file() && !path.is_symlink() { return path; }
+        if path.is_file() && !path.is_symlink() { return Some(path); }
     }
-    if moonarch_wallpaper.is_file() { return moonarch_wallpaper.to_path_buf(); }
-    PathBuf::from(format!("{GRESOURCE_PREFIX}/wallpaper.jpg"))
+    if moonarch_wallpaper.is_file() { return Some(moonarch_wallpaper.to_path_buf()); }
+    None
 }
 
 #[cfg(test)]
@@ -109,7 +108,7 @@ mod tests {
         let dir = tempfile::tempdir().unwrap();
         let wp = dir.path().join("bg.jpg"); fs::write(&wp, "fake").unwrap();
         let c = Config { background_path: Some(wp.to_str().unwrap().to_string()), ..Config::default() };
-        assert_eq!(resolve_background_path_with(&c, Path::new("/nonexistent")), wp);
+        assert_eq!(resolve_background_path_with(&c, Path::new("/nonexistent")), Some(wp));
     }
     #[test] fn empty_user_config_preserves_system_fingerprint() {
         let dir = tempfile::tempdir().unwrap();
@@ -120,10 +119,10 @@ mod tests {
         let c = load_config(Some(&[sys_conf, usr_conf]));
         assert!(!c.fingerprint_enabled);
     }
-    #[test] fn resolve_gresource_fallback() {
+    #[test] fn resolve_no_wallpaper_returns_none() {
         let c = Config::default();
         let r = resolve_background_path_with(&c, Path::new("/nonexistent"));
-        assert!(r.to_str().unwrap().contains("moonlock"));
+        assert!(r.is_none());
     }
     #[test] fn toml_parse_error_returns_default() {
         let dir = tempfile::tempdir().unwrap();
@@ -141,8 +140,8 @@ mod tests {
         fs::write(&real, "fake").unwrap();
         std::os::unix::fs::symlink(&real, &link).unwrap();
         let c = Config { background_path: Some(link.to_str().unwrap().to_string()), ..Config::default() };
-        // Symlink should be rejected — falls through to moonarch wallpaper or gresource
+        // Symlink should be rejected — falls through to None
         let r = resolve_background_path_with(&c, Path::new("/nonexistent"));
-        assert_ne!(r, link);
+        assert!(r.is_none());
     }
 }

src/lockscreen.rs

@@ -44,7 +44,7 @@ struct LockscreenState {
 /// The `blur_cache` and `avatar_cache` are shared across monitors for multi-monitor
 /// setups, avoiding redundant GPU renders and SVG rasterizations.
 pub fn create_lockscreen_window(
-    bg_texture: &gdk::Texture,
+    bg_texture: Option<&gdk::Texture>,
     config: &Config,
     app: &gtk::Application,
     unlock_callback: Rc<dyn Fn()>,
@@ -86,9 +86,11 @@ pub fn create_lockscreen_window(
     let overlay = gtk::Overlay::new();
     window.set_child(Some(&overlay));
 
-    // Background wallpaper
-    let background = create_background_picture(bg_texture, config.background_blur, blur_cache);
-    overlay.set_child(Some(&background));
+    // Background wallpaper (if available — otherwise GTK background color shows through)
+    if let Some(texture) = bg_texture {
+        let background = create_background_picture(texture, config.background_blur, blur_cache);
+        overlay.set_child(Some(&background));
+    }
 
     // Centered vertical box
     let main_box = gtk::Box::new(gtk::Orientation::Vertical, 0);
@@ -430,18 +432,16 @@ pub fn start_fingerprint(
 }
 
 /// Load the wallpaper as a texture once, for sharing across all windows.
+/// Returns None if no wallpaper path is provided or the file cannot be loaded.
 /// Blur is applied at render time via GPU (GskBlurNode), not here.
-pub fn load_background_texture(bg_path: &Path) -> gdk::Texture {
-    let fallback = "/dev/moonarch/moonlock/wallpaper.jpg";
-
-    if bg_path.starts_with("/dev/moonarch/moonlock") {
-        let resource_path = bg_path.to_str().unwrap_or(fallback);
-        gdk::Texture::from_resource(resource_path)
-    } else {
-        let file = gio::File::for_path(bg_path);
-        gdk::Texture::from_file(&file).unwrap_or_else(|_| {
-            gdk::Texture::from_resource(fallback)
-        })
+pub fn load_background_texture(bg_path: &Path) -> Option<gdk::Texture> {
+    let file = gio::File::for_path(bg_path);
+    match gdk::Texture::from_file(&file) {
+        Ok(texture) => Some(texture),
+        Err(e) => {
+            log::warn!("Failed to load wallpaper {}: {e}", bg_path.display());
+            None
+        }
     }
 }
 

src/main.rs

@@ -40,16 +40,16 @@ fn activate(app: &gtk::Application) {
     load_css(&display);
 
     let config = config::load_config(None);
-    let bg_path = config::resolve_background_path(&config);
-    let bg_texture = lockscreen::load_background_texture(&bg_path);
+    let bg_texture = config::resolve_background_path(&config)
+        .and_then(|path| lockscreen::load_background_texture(&path));
 
     if gtk4_session_lock::is_supported() {
-        activate_with_session_lock(app, &display, &bg_texture, &config);
+        activate_with_session_lock(app, &display, bg_texture.as_ref(), &config);
     } else {
         #[cfg(debug_assertions)]
         {
             log::warn!("ext-session-lock-v1 not supported — running in development mode");
-            activate_without_lock(app, &bg_texture, &config);
+            activate_without_lock(app, bg_texture.as_ref(), &config);
         }
         #[cfg(not(debug_assertions))]
         {
@@ -62,7 +62,7 @@ fn activate(app: &gtk::Application) {
 fn activate_with_session_lock(
     app: &gtk::Application,
     display: &gdk::Display,
-    bg_texture: &gdk::Texture,
+    bg_texture: Option<&gdk::Texture>,
     config: &config::Config,
 ) {
     let lock = gtk4_session_lock::Instance::new();
@@ -158,7 +158,7 @@ fn init_fingerprint_async(all_handles: Vec<lockscreen::LockscreenHandles>) {
 #[cfg(debug_assertions)]
 fn activate_without_lock(
     app: &gtk::Application,
-    bg_texture: &gdk::Texture,
+    bg_texture: Option<&gdk::Texture>,
     config: &config::Config,
 ) {
     let app_clone = app.clone();