feat(editor): replace emoji picker with browse + search (#2171)

* feat(editor): show emoji name in suggestion list

Replace the fixed-column emoji grid with a vertical list that displays
each emoji alongside its :shortcode: name. This makes the picker more
discoverable—users can see and learn shortcodes without prior knowledge.

Changes:
- EmojiList: switch from SimpleGrid/ActionIcon to UnstyledButton list
  rows showing emoji glyph + monospace 🆔 label
- Navigation simplified to ArrowUp/ArrowDown (list has no columns)
- Results capped at 8 items for a focused, scannable dropdown
- CSS module: rename menuBtn -> menuItem, tighten padding

* feat(editor): replace SearchIndex with name/id includes search

Port the exact search algorithm from the original extension:
- Build a flat index from @emoji-mart/data: { id, name (lowercase), native }
- Filter with name.includes(q) || id.includes(q) — predictable, no
  keyword indirection
- Results capped at 5 (same as extension)
- Frequently-used emojis (sorted by usage) shown when query is empty
- Remove emoji-mart init() / SearchIndex / getEmojiDataFromNative
  dependencies; index is built lazily and cached in memory
- Remove unused GRID_COLUMNS constant

* feat(editor): emoji picker with browse and search modes

When the query is empty the picker shows a category bar with 8 tabs
(people, nature, food…) and a scrollable emoji grid. Typing after ':'
switches to a compact list that shows the glyph and :shortcode: side by
side, making it easy to discover emoji names while you type.

- Category data is loaded lazily from @emoji-mart/data and cached, so
  opening the picker more than once has no overhead
- Grid keyboard nav: arrow keys move by cell/row, Enter picks
- List keyboard nav: up/down through results, Enter picks
- Mouse hover syncs the keyboard selection index in both modes
- incrementEmojiUsage tracks picks so frequently used ones bubble up
  in future sessions

* fix(editor): polish emoji picker copy and loading

* feat: add emoji to slash command

* Add keyboard support to emoji group navigation

---------

Co-authored-by: Philipinho <16838612+Philipinho@users.noreply.github.com>

apps/client/src/features/editor/components/slash-menu/menu-items.ts

@@ -25,6 +25,7 @@ import {
   IconColumns3,
   IconColumns2,
   IconTag,
+  IconMoodSmile,
   IconRotate2,
 } from "@tabler/icons-react";
 import {
@@ -477,6 +478,15 @@ const CommandGroups: SlashMenuGroupedItemsType = {
           .run();
       },
     },
+    {
+      title: "Emoji",
+      description: "Insert emoji.",
+      searchTerms: ["emoji", "icon", "smiley", "emoticon", "symbol", "reaction"],
+      icon: IconMoodSmile,
+      command: ({ editor, range }: CommandProps) => {
+        editor.chain().focus().deleteRange(range).insertContent(":").run();
+      },
+    },
     {
       title: "Subpages (Child pages)",
       description: "List all subpages of the current page",