fix(status): unicode-only emoji picker (custom emojis silently did nothing)

The status-message emoji picker listed the guild's custom/image-pack emojis, but
clicking one did nothing — the field only wires onEmojiSelect (unicode), not
onCustomEmojiSelect, so custom picks were silently dropped (the room composer
works because it wires both). A custom emoji is an mxc image and a status is
plain-text presence status_msg, so it can't render there anyway.

Add an EmojiBoard hideCustomEmojis (unicode-only) mode that zeroes the image
packs (removing pack groups, sidebar icons, and search results) and filters
custom entries out of Recent, and enable it on the status field. Now every emoji
shown actually inserts. Additive prop, default off — no change to other pickers.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

LOTUS_FEATURES.md

@@ -950,6 +950,7 @@ A presence status selector in the user panel offering five modes:
 ### Custom Status Message
 
 - Up to 64 characters of free text plus an emoji
+- **Emoji picker is unicode-only** (`EmojiBoard hideCustomEmojis`): a status is plain-text presence (`status_msg`) that can't render a custom mxc-image emoji, so the picker hides custom/image-pack emojis (packs, sidebar icons, search, and custom entries in Recent) — every emoji shown actually inserts. (Previously custom emojis were listed but silently did nothing when clicked, since there was no `onCustomEmojiSelect` on this field.)
 - Optional auto-clear timer with presets: 30 minutes, 1 hour, 4 hours, 1 day, 3 days, 7 days
 - Status is broadcast via `mx.setPresence({ status_msg: ... })`
 - Character counter appears at 56/64 characters remaining to warn of the limit