What is transaction introspection in Kaspa's KIP17?

Transaction introspection in KIP17 means Kaspa scripts can read details from the transaction that is trying to spend them — things like the transaction version, lock time, subnet ID, input amounts, and output scripts. These introspection opcodes act like windows into the spending transaction: a script can look inside and check what the transaction actually contains, not just whether a valid signature was provided. This matters for beginners because introspection is the foundation that makes covenant enforcement possible — a script cannot verify rules about amounts and destinations unless it can first read those values.