feat(chat): add a dragon-themed emoji set to the picker

Adds 🐉 🐲 🐍 🦎 🐊 🐾 🥚 🪺 🏰 ⚔ 🛡 🗡 to the emoji picker, with DRGX-flavoured
keywords (the dragons are searchable by "dragon"/"drgx"). All are single-codepoint
emoji verified present in both the bundled monochrome NotoEmoji subset and the
color Twemoji font, so no font rebuild is needed and they render on other clients
(standard Unicode, UTF-8 in the memo, within the 236-byte cap).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/ui/windows/chat_tab.cpp

@@ -539,6 +539,13 @@ static const EmojiEntry kEmoji[] = {
     {u8"🤢","nausea sick"},{u8"🤮","vomit sick"},{u8"🤧","sneeze sick"},{u8"😷","mask sick"},{u8"🤒","sick thermometer"},
     {u8"🤕","hurt bandage injured"},{u8"😈","devil imp evil"},{u8"👿","devil angry"},{u8"💀","skull dead"},{u8"👻","ghost boo"},
     {u8"👽","alien"},{u8"🤖","robot bot"},{u8"😺","cat smile"},{u8"🙀","cat scream"},
+    // Dragon-themed set (DRGX flavour — searchable by "dragon"/"drgx"). All verified present in the
+    // bundled mono NotoEmoji subset + the color Twemoji font.
+    {u8"🐉","dragon drgx dragonx wyrm mythical creature"},{u8"🐲","dragon face drgx dragonx"},
+    {u8"🐍","snake serpent reptile"},{u8"🦎","lizard reptile gecko"},{u8"🐊","crocodile croc reptile gator"},
+    {u8"🐾","paw tracks claws prints"},{u8"🥚","egg dragon egg"},{u8"🪺","nest eggs hatch"},
+    {u8"🏰","castle lair fortress keep"},{u8"⚔","swords battle crossed fight"},
+    {u8"🛡","shield defense guard protect"},{u8"🗡","dagger blade sword knife"},
     {u8"👍","thumbs up like yes good"},{u8"👎","thumbs down dislike no bad"},{u8"👌","ok perfect"},{u8"✌","peace victory"},
     {u8"🤞","fingers crossed luck"},{u8"🤟","love you"},{u8"🤘","rock horns"},{u8"👏","clap applause"},
     {u8"🙌","raise hands celebrate"},{u8"👐","open hands"},{u8"🙏","pray thanks please"},{u8"💪","muscle strong flex"},