fix: drop every local reference to a channel message that was deleted (#30314)

src/lib/components/channel/Channel.svelte

@@ -168,7 +168,17 @@
 					messages[idx] = data;
 				}
 			} else if (type === 'message:delete') {
-				messages = messages.filter((message) => message.id !== data.id);
+				messages = messages
+					.filter((message) => message.id !== data.id)
+					.map((message) =>
+						message?.reply_to_message?.id === data.id
+							? { ...message, reply_to_message: null }
+							: message
+					);
+
+				if (replyToMessage?.id === data.id) {
+					replyToMessage = null;
+				}
 
 				if (threadId === data.id) {
 					threadId = null;

src/lib/components/channel/Thread.svelte

@@ -92,7 +92,17 @@
 				}
 
 				if (messages) {
-					messages = messages.filter((message) => message.id !== data.id);
+					messages = messages
+						.filter((message) => message.id !== data.id)
+						.map((message) =>
+							message?.reply_to_message?.id === data.id
+								? { ...message, reply_to_message: null }
+								: message
+						);
+				}
+
+				if (replyToMessage?.id === data.id) {
+					replyToMessage = null;
 				}
 			} else if (type.includes('message:reaction')) {
 				if (messages) {