feat(gif): outlined GIF glyph, and GIF picker for the profile banner

The composer's GIF button drew a filled rounded rect with the letters knocked
out, which reads as a solid square rather than a picker. Invert it: stroked
outline with filled letters, reusing the original glyph paths scaled to centre.

Banners already accept absolute URLs on both ends (server isValidAssetUrl
allows http(s); the profile render branches on banner.startsWith('http')), so
the picker stores the remote URL directly with no upload path. Previews can now
hold either a blob: or an https: URL, so revoking is guarded — calling
revokeObjectURL on a remote URL is a silent no-op that would hide a mistake.

packages/web/src/components/chat/MessageInput.tsx

@@ -959,8 +959,14 @@ export function MessageInput({ channelId, channelName, placeholder }: MessageInp
               title="GIF"
               aria-label="GIF picker"
             >
-              <svg width="18" height="18" viewBox="0 0 24 24" fill="currentColor">
-                <path d="M2 5.5A2.5 2.5 0 0 1 4.5 3h15A2.5 2.5 0 0 1 22 5.5v13a2.5 2.5 0 0 1-2.5 2.5h-15A2.5 2.5 0 0 1 2 18.5v-13ZM5.1 14V10h3.2v1.2H6.5v.6h1.6v1.1H6.5V14H5.1Zm4.5 0V10h1.4v4H9.6Zm2.5 0V10h3.2v1.2h-1.8v.5h1.6v1h-1.6V14h-1.4Z" />
+              {/* Outlined badge, not a filled block: the solid rectangle read as
+                  a plain square rather than a GIF picker. Letters reuse the
+                  original glyph paths, scaled and centred inside the outline. */}
+              <svg width="20" height="20" viewBox="0 0 24 24" fill="none" aria-hidden="true">
+                <rect x="3" y="6" width="18" height="12" rx="3" stroke="currentColor" strokeWidth="2" />
+                <g fill="currentColor" transform="translate(-1.77 -4.2) scale(1.35)">
+                  <path d="M5.1 14V10h3.2v1.2H6.5v.6h1.6v1.1H6.5V14H5.1Zm4.5 0V10h1.4v4H9.6Zm2.5 0V10h3.2v1.2h-1.8v.5h1.6v1h-1.6V14h-1.4Z" />
+                </g>
               </svg>
             </button>
           )}

packages/web/src/components/modals/settingsPanels/AccountPanel.tsx

@@ -5,6 +5,7 @@ import { useInstanceStore } from '../../../stores/instanceStore';
 import { useSpaceStore } from '../../../stores/spaceStore';
 import { Avatar } from '../../ui/Avatar';
 import { ImageCropModal } from '../../ui/ImageCropModal';
+import { GifPicker } from '../../chat/GifPicker';
 import { DeleteAccountModal } from '../DeleteAccountModal';
 import { api } from '../../../api/client';
 import { useTransferStore } from '../../../stores/transferStore';
@@ -13,6 +14,16 @@ import { getAvatarGradient, adjustColor, mutedGradient, AVATAR_GRADIENT_MAP, BAN
 import { AVATAR_COLORS } from '@backspace/shared';
 import type { User, UserStatus, AvatarColor } from '@backspace/shared';
 import type { FederationOpResult } from '../../../utils/federationOps';
+/**
+ * Banner/avatar previews hold either a `blob:` object URL (local upload) or a
+ * remote `https:` URL (GIF picker). Only the former owns memory that must be
+ * released — calling revokeObjectURL on a remote URL is a silent no-op that
+ * would quietly hide a mistake here.
+ */
+function releasePreview(url: string | null): void {
+  if (url && url.startsWith('blob:')) URL.revokeObjectURL(url);
+}
+
 export function AccountPanel() {
   const user = useAuthStore((s) => s.user);
   const updateProfile = useAuthStore((s) => s.updateProfile);
@@ -37,6 +48,7 @@ export function AccountPanel() {
   const [bannerFilename, setBannerFilename] = useState<string | null>(null);
   const [uploadingBanner, setUploadingBanner] = useState(false);
   const [bannerCropSrc, setBannerCropSrc] = useState<string | null>(null);
+  const [showBannerGif, setShowBannerGif] = useState(false);
   const bannerInputRef = useRef<HTMLInputElement>(null);
 
   const addToast = useUIStore((s) => s.addToast);
@@ -54,7 +66,7 @@ export function AccountPanel() {
       setCustomHex(user.accentColor ?? '');
       // Reset upload state
       if (avatarPreview) URL.revokeObjectURL(avatarPreview);
-      if (bannerPreview) URL.revokeObjectURL(bannerPreview);
+      releasePreview(bannerPreview);
       setAvatarPreview(null);
       setAvatarFilename(null);
       setBannerPreview(null);
@@ -202,7 +214,7 @@ export function AccountPanel() {
   };
 
   const handleBannerCropComplete = async (blob: Blob) => {
-    if (bannerPreview) URL.revokeObjectURL(bannerPreview);
+    releasePreview(bannerPreview);
     const previewUrl = URL.createObjectURL(blob);
     setBannerPreview(previewUrl);
     setBannerCropSrc(null);
@@ -227,8 +239,21 @@ export function AccountPanel() {
     setAvatarFilename('');
   };
 
+  /**
+   * Banners accept absolute URLs end to end: the server's isValidAssetUrl
+   * allows http(s), and the profile render already branches on
+   * `banner.startsWith('http')`. So a picked GIF needs no upload — the remote
+   * URL is stored directly.
+   */
+  const handleBannerGifSelect = (url: string) => {
+    releasePreview(bannerPreview);
+    setBannerPreview(url);
+    setBannerFilename(url);
+    setShowBannerGif(false);
+  };
+
   const handleRemoveBanner = () => {
-    if (bannerPreview) URL.revokeObjectURL(bannerPreview);
+    releasePreview(bannerPreview);
     setBannerPreview(null);
     setBannerFilename('');
   };
@@ -300,7 +325,7 @@ export function AccountPanel() {
     setAvatarColorState(user.avatarColor ?? null);
     setCustomHex(user.accentColor ?? '');
     if (avatarPreview) URL.revokeObjectURL(avatarPreview);
-    if (bannerPreview) URL.revokeObjectURL(bannerPreview);
+    releasePreview(bannerPreview);
     setAvatarPreview(null);
     setAvatarFilename(null);
     setBannerPreview(null);
@@ -482,7 +507,7 @@ export function AccountPanel() {
                 </div>
               )}
             </button>
-            <div className="flex gap-2 mt-1">
+            <div className="relative flex gap-2 mt-1">
               <button
                 type="button"
                 onClick={() => bannerInputRef.current?.click()}
@@ -491,6 +516,23 @@ export function AccountPanel() {
               >
                 Change Banner
               </button>
+              <button
+                type="button"
+                onClick={() => setShowBannerGif((v) => !v)}
+                disabled={uploadingBanner}
+                className="text-xs text-accent-primary hover:underline"
+              >
+                Choose GIF
+              </button>
+              {showBannerGif && (
+                <>
+                  {/* Click-away layer, below the panel but above the page */}
+                  <div className="fixed inset-0 z-[290]" onClick={() => setShowBannerGif(false)} />
+                  <div className="absolute left-0 top-full mt-2 z-[300] glass rounded-xl overflow-hidden">
+                    <GifPicker onGifSelect={handleBannerGifSelect} />
+                  </div>
+                </>
+              )}
               {(displayBannerSrc || user.banner) && bannerFilename !== '' && (
                 <button
                   type="button"