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

wwwroot/main.js

@@ -131,6 +131,26 @@ window.copyText = async text => {
 		return false
 	}
 }
+// where a text field's selection starts and ends (the composer writes an emoji there); null when it can't say
+window.caretOf = field => {
+	try {
+		return typeof field?.selectionStart == "number" ? [field.selectionStart, field.selectionEnd] : null
+	} catch (e) {
+		console.error(e)
+		window.logFromJs(e.message, "caretOf")
+		return null
+	}
+}
+// the field takes the focus with its caret at that offset (after the emoji just written)
+window.placeCaret = (field, at) => {
+	try {
+		field?.focus()
+		field?.setSelectionRange(at, at)
+	} catch (e) {
+		console.error(e)
+		window.logFromJs(e.message, "placeCaret")
+	}
+}
 // a phone: narrower than Tailwind's md, or held sideways (as short as the short: variant)
 window.isMobileMedia = () => {
 	try {