fix(avatar): gracefully degrade when avatar directory is not writable

AppAvatar::init() create_dir_all failure now logs a warning instead of
failing fatally. This fixes the email worker crash — it runs AppService
but has no PVC mount, so /data/avatars is not accessible. Other services
(app) have the PVC mounted and are unaffected.

libs/avatar/lib.rs

@@ -17,7 +17,9 @@ impl AppAvatar {
     pub async fn init(cfg: &AppConfig) -> anyhow::Result<Self> {
         let path = cfg.avatar_path()?;
         if std::fs::read_dir(&path).is_err() {
-            std::fs::create_dir_all(&path)?;
+            if let Err(e) = std::fs::create_dir_all(&path) {
+                tracing::warn!(path = %path, error = %e, "Avatar directory not available, avatars disabled");
+            }
         }
         let basic_path = PathBuf::from(path);
         Ok(Self { basic_path })