feat(shard): ✨ Prevent non-participants from hanging up or skipping calls.

payphone/cogs/calls/cog.py

@@ -73,6 +73,15 @@ class Calls(base.Cog):
                 f"☎️ You're not on a call! Use `{ctx.clean_prefix}call` to start one."
             )
 
+        call = await self.bot.call_handler.get_call_by_channel_id(ctx.channel.id)
+
+        participant = await call.get_participant(ctx.author.id)
+
+        if participant is None:
+            return await ctx.send(
+                "❌ You cannot skip a call you have not participated in."
+            )
+
         channels = await self.bot.call_handler.skip(ctx.channel.id)
 
         for channel in channels:
@@ -104,6 +113,15 @@ class Calls(base.Cog):
                 f"☎️ You're not on a call! Use `{ctx.clean_prefix}call` to start one."
             )
 
+        call = await self.bot.call_handler.get_call_by_channel_id(ctx.channel.id)
+
+        participant = await call.get_participant(ctx.author.id)
+
+        if participant is None:
+            return await ctx.send(
+                "❌ You cannot hang up a call you have not participated in."
+            )
+
         channels = await self.bot.call_handler.hangup(ctx.channel.id)
 
         other_channel = channels[0] if channels[0] != ctx.channel.id else channels[1]