Fix parse mode: use enums.ParseMode.HTML instead of string

ParseMode is a plain Enum, not a str subclass — string "html" fails
equality check against the enum member and raises ValueError.

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

app/commands/builtins.py

@@ -5,6 +5,8 @@ import re
 from textwrap import wrap
 from typing import TYPE_CHECKING, Any
 
+from pyrogram import enums
+
 from app.ai import AIInvocation, parse_ai_invocation
 from app.commands.core import CommandRegistry, normalize_command_name
 
@@ -106,12 +108,12 @@ async def _reply_long(ctx: "CommandContext", text: str) -> None:
         await ctx.reply("")
         return
     html_chunks = [f"<blockquote>{_md_to_tg(c)}</blockquote>" for c in chunks]
-    first = await ctx.reply(html_chunks[0], parse_mode="html")
+    first = await ctx.reply(html_chunks[0], parse_mode=enums.ParseMode.HTML)
     for chunk in html_chunks[1:]:
         await ctx.client.send_message(
             ctx.message.chat.id,
             chunk,
-            parse_mode="html",
+            parse_mode=enums.ParseMode.HTML,
             reply_to_message_id=getattr(first, "id", None),
         )