hangman: fix display never showing guessed letters + improve word-guess feedback

- _hangman_display compared uppercase word chars against lowercase
  guessed_letters set, so letters were never revealed after correct guesses
- Word guess wrong path now shows the board and remaining guesses
- Winner display now includes the guesser's name on correct word guess

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

matrixbot/commands.py

@@ -1226,8 +1226,8 @@ _HANGMAN_STAGES = [
 
 def _hangman_display(game: dict) -> str:
     word = game["word"]
-    guessed = game["guessed_letters"]
-    return " ".join(c if c in guessed else "_" for c in word.upper())
+    guessed = game["guessed_letters"]  # stored lowercase
+    return " ".join(c if c.lower() in guessed else "_" for c in word.upper())
 
 
 async def _generate_hangman_word() -> dict | None:
@@ -1340,24 +1340,36 @@ async def cmd_guess(client: AsyncClient, room_id: str, sender: str, args: str):
 
     # Full word guess
     if len(guess) > 1:
+        winner = sender.split(":")[0].lstrip("@")
         if guess == word:
             del _HANGMAN_GAMES[room_id]
-            plain = f"🎉 {sender.split(':')[0].lstrip('@')} got it! The word was: {word.upper()}"
+            plain = f"🎉 {winner} got it! The word was: {word.upper()}"
             html = (
-                f'<font color="#22c55e"><strong>🎉 Correct! The word was: {word.upper()}</strong></font><br>'
-                f'Guessed by {sender.split(":")[0].lstrip("@")}!'
+                f'<font color="#22c55e"><strong>🎉 {winner} got it! The word was: {word.upper()}</strong></font>'
             )
             await send_html(client, room_id, plain, html)
         else:
             game["wrong_count"] += 1
+            display = _hangman_display(game)
             if game["wrong_count"] >= 6:
                 del _HANGMAN_GAMES[room_id]
-                plain = f"❌ Wrong! Game over — the word was: {word.upper()}"
+                plain = f"❌ '{guess.upper()}' is wrong! Game over — the word was: {word.upper()}"
                 html = f'<font color="#ef4444"><strong>❌ Wrong! Game over — the word was: {word.upper()}</strong></font>'
                 await send_html(client, room_id, plain, html)
             else:
                 remaining = 6 - game["wrong_count"]
-                await send_text(client, room_id, f"❌ '{guess.upper()}' is wrong! {remaining} wrong guesses remaining.")
+                plain = (
+                    f"❌ '{guess.upper()}' is wrong! {remaining} guesses remaining.\n"
+                    f"{_HANGMAN_STAGES[game['wrong_count']]}\n"
+                    f"Word: {display}\nHint: {game['hint']}"
+                )
+                html = (
+                    f'<font color="#ef4444"><strong>❌ \'{guess.upper()}\' is wrong!</strong></font> '
+                    f'{remaining} guesses remaining.<br>'
+                    f'<strong>Word:</strong> <code>{display}</code><br>'
+                    f'<strong>Hint:</strong> {game["hint"]}'
+                )
+                await send_html(client, room_id, plain, html)
         return
 
     # Single letter guess