R7 custom emoji in decePub: the server's own, administered, picked, suggested and shown

Administration has a Custom emoji section (EmojiPanel, data-admin-section=emoji): the server's emoji by category, added
with a picture streamed from the file, changed (category, picker, disabled, picture; never the shortcode) and deleted,
asked first, with PrivaPub's 409 and 422 in the dialog. EmojiService reads /clientapi/admin/emoji and, for everyone,
/api/v1/custom_emojis, kept a day in localStorage (CustomEmojiCache) and read again after a change here. EmojiPicker
(a DDropdown sheet on a phone, rendered only while open) offers them by category with common unicode emoji, searchable:
the composer writes the choice at the caret, a card and the announcements banner react with it. The composer suggests
custom emoji after `:` and two letters. Custom reactions toggle as :shortcode: and show their picture, notifications of
one too; located posts, announcements and NavMenu's persona names render the server's emoji.

Verified: Release build, 0 errors (the 3 warnings were there before). Not run against PrivaPub or in the pasture.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WpVCoDeM1qUTRp4fXQdfof

Pages/Administration.razor

@@ -6,8 +6,8 @@
 
 @* Moderators handle reports, moderate accounts here and elsewhere (Accounts) and read the staff's log. Administrators
    also change the logins and their personas (Users & personas), say what the server is (Instance), set its rules, write
-   its announcements, block servers for everyone, choose its relays and media limits, read the federation statistics, and
-   back up and restore the server. PrivaPub checks the role on every call; the sections only follow it. Each section is
+   its announcements, add its custom emoji, block servers for everyone, choose its relays and media limits, read the
+   federation statistics, and back up and restore the server. PrivaPub checks the role on every call; the sections only follow it. Each section is
    a collapse marked data-admin-section; its panel loads when the page opens. *@
 <section class="block relative w-full h-full neo-inset neo-xs rounded-xl">
 
@@ -105,6 +105,19 @@
 				</ChildContent>
 			</DCollapse>
 
+			<DCollapse Icon="DCollapseIcon.Arrow" data-admin-section="emoji">
+				<Header>
+					<p class="inline-flex items-center gap-2">
+						<i class="ion-md-happy text-xl"></i> <span>@Localizer["Custom emoji"]</span>
+					</p>
+				</Header>
+				<ChildContent>
+					<div class="block w-full p-3 md:p-4">
+						<EmojiPanel />
+					</div>
+				</ChildContent>
+			</DCollapse>
+
 			<DCollapse Icon="DCollapseIcon.Arrow" data-admin-section="blocks">
 				<Header>
 					<p class="inline-flex items-center gap-2">