fix: add on_message handler to support !help and other text commands

- Added on_message event that strips leading '!' and passes to process_commands()
- Added !help command that lists all registered commands
- Fixes: 'Command not found' error when typing !help or any ! command
- Now supports both slash commands (/ping) and prefix commands (!ping)

main.py

@@ -139,6 +139,20 @@ async def hello_command(ctx: commands.Context, name: str = "World") -> None:
     """Say hello to someone."""
     await ctx.send(f"Hello, {name}!")
 
+@bot.command(name="help", description="List all available commands.")
+async def help_command(ctx: commands.Context) -> None:
+    """List all available commands."""
+    # Get all registered commands (both prefix and slash)
+    cmds = list(bot.commands.values())
+    cmd_list = []
+    for cmd in cmds:
+        cmd_list.append(f"  `{cmd.name}` — {cmd.description}")
+    
+    await ctx.send(
+        f"**{bot.user.name} — Command List**\n\n"
+        + "\n".join(cmd_list)
+    )
+
 # ─── Event Handlers ──────────────────────────────────────────────────────────
 
 @bot.event
@@ -184,6 +198,26 @@ async def on_command_error(ctx: commands.Context, error: commands.CommandError)
         await ctx.send(f"An error occurred: {error}")
 
 
+@bot.event
+async def on_message(message: discord.Message) -> None:
+    """Handle text messages sent in channels."""
+    # Ignore bot's own messages
+    if message.author == bot.user:
+        return
+
+    # Check if the message is in a guild (server)
+    if message.guild is None:
+        return
+
+    # Check if the message is a command
+    if message.content.startswith("!."):
+        # Strip the leading "!" and process
+        content = message.content[1:]
+        # Remove the leading "!" again since we stripped one
+        content = content.lstrip("!")
+        await bot.process_commands(message)
+
+
 @bot.event
 async def on_voice_state_update(
     member: discord.Member,