feat: avatars for humans (#273)

* implement avatar backend functionality

* add avatar endpoints

* typo

* implement client side avatar upload and handling

* fixes

* Update go/internal/handler/handler.go

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* Update js/desktop/src/lib/avatar-image.ts

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

* bug in order

* remove unused component

* fix invalid migration

* fix syntax errors

---------

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

js/desktop/src/components/human-avatar.tsx

@@ -0,0 +1,36 @@
+import * as React from 'react';
+import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';
+import { useAvatarUrl } from '@/hooks/use-avatar-url';
+
+interface HumanAvatarProps extends Omit<
+  React.ComponentProps<typeof Avatar>,
+  'children'
+> {
+  /** Object id of the human's profile picture, if any. */
+  avatarObjectId?: string | null;
+  /** Initials rendered while loading or when no picture is set. */
+  initials: string;
+  /** Extra classes for the initials fallback. */
+  fallbackClassName?: string;
+}
+
+/**
+ * Renders a human's avatar: their profile picture when set (resolved to a
+ * signed URL), otherwise their initials. The fallback also shows while the
+ * image loads or if it fails, so this is a drop-in for the initials-only
+ * <Avatar> usages throughout the app.
+ */
+export function HumanAvatar({
+  avatarObjectId,
+  initials,
+  fallbackClassName,
+  ...props
+}: HumanAvatarProps) {
+  const url = useAvatarUrl(avatarObjectId);
+  return (
+    <Avatar {...props}>
+      {url && <AvatarImage src={url} alt={initials} />}
+      <AvatarFallback className={fallbackClassName}>{initials}</AvatarFallback>
+    </Avatar>
+  );
+}