feat(subsonic): add avatar support

closes: #228

server/assets/static/main.css

@@ -178,3 +178,9 @@ a:hover {
 .angry {
   background-color: #f4433669;
 }
+
+.avatar-preview {
+  width: 64px;
+  height: 64px;
+  object-fit: cover;
+}

server/assets/static/main.js

@@ -0,0 +1,5 @@
+for (const form of document.querySelectorAll("form.file-upload") || []) {
+  const input = form.querySelector("input[type=file]");
+  if (!input) continue;
+  input.onchange = (e) => form.submit();
+}

server/assets/static/playlist-upload.js

@@ -1,3 +0,0 @@
-document.getElementById("playlist-upload-input").onchange = e => {
-  document.getElementById("playlist-upload-form").submit();
-};