fix(test): UTXO timelock >= -> >

Time needs to be greater than release data, not greater than
or equal to.

Also adds a test that this is how the consensus program type script is
implemented.

src/models/blockchain/transaction/utxo.rs

@@ -308,7 +308,10 @@ mod utxo_tests {
         prop_assert!(!utxo.can_spend_at(release_date - delta));
         prop_assert!(utxo.is_timelocked_but_otherwise_spendable_at(release_date - delta));
 
-        prop_assert!(utxo.can_spend_at(release_date));
+        let epsilon = Timestamp::millis(1);
+        prop_assert!(!utxo.can_spend_at(release_date - epsilon));
+        prop_assert!(!utxo.can_spend_at(release_date));
+        prop_assert!(utxo.can_spend_at(release_date + epsilon));
         prop_assert!(utxo.can_spend_at(release_date + delta));
         prop_assert!(!utxo.is_timelocked_but_otherwise_spendable_at(release_date + delta));
     }

src/models/blockchain/type_scripts/time_lock.rs

@@ -1051,9 +1051,12 @@ fn arbitrary_primitive_witness_with_timelocks(
 mod test {
     use num_traits::Zero;
     use proptest::collection::vec;
+    use proptest::prelude::Arbitrary;
+    use proptest::prelude::Strategy;
     use proptest::prop_assert;
     use proptest::prop_assert_eq;
     use proptest::strategy::Just;
+    use proptest::test_runner::TestRunner;
     use proptest_arbitrary_interop::arb;
     use test_strategy::proptest;
     use tokio::runtime::Runtime;
@@ -1097,6 +1100,36 @@ mod test {
         prop_assert_eq!(rust_result.unwrap(), tasm_result.unwrap());
     }
 
+    #[test]
+    fn tx_timestamp_same_as_release_time_must_fail() {
+        // Verify use of `>`, not `>=`.
+        let release_date = Timestamp::now();
+        let mut test_runner = TestRunner::deterministic();
+        let time_lock_witness =
+            TimeLockWitness::arbitrary_with((vec![release_date], 1, 0, release_date))
+                .new_tree(&mut test_runner)
+                .unwrap()
+                .current();
+        assert!(
+            TimeLock {}
+                .run_rust(
+                    &time_lock_witness.standard_input(),
+                    time_lock_witness.nondeterminism(),
+                )
+                .is_err(),
+            "time lock program failed to panic"
+        );
+        assert!(
+            TimeLock {}
+                .run_tasm(
+                    &time_lock_witness.standard_input(),
+                    time_lock_witness.nondeterminism(),
+                )
+                .is_err(),
+            "time lock program failed to panic"
+        );
+    }
+
     #[proptest(cases = 20)]
     fn test_locked(
         #[strategy(1usize..=3)] _num_inputs: usize,