When TN and K were seen as 'in this order, only' is question that cannot be answered without discussing the canonisation process. Canonisation is a process with many stages of considerable fluidity. Our lack of original documents renders any definitive assertion dubious. But as close as we can get:
Since the Samaritans are the guardians of the true Tora, and the only and complete collection of the 5 books of Mose, we can conclude that around the time of the split between Samaritans and mainstream Judaism between 400 and 300 BC mainstream Judaism started to regard other writings as tora, ie scripture, which the Samaritans rejected.
For the later mainstream Jews this addition to tora – the nomos in Greek or law in English – were then 'the prophets' – giving rise to the primacy of 'the law' (T) to the additions, or the rendering of "the law and the prophets" as we know it from the New Testament.
But what is "tora" in the first place? It is not just 'the Tora', not "a law" but also a teaching, and holy scripture. Looking at the texts found at Qumran, we have to conclude that the five books were already in the canon, but not the canon, and other writings were not considered Tora but tora. Never first place though.
The very fact that "the law and the prophets" is a standing expression in the New Testament indicates this two-partite organisation to be contemporary to the time of Jesus.
At roughly the same time we again look at Qumran (4Q397,10) and find the early formula of "the books of Mose, the prophets and David. Equally in Lukas 24:44 we find "the law of Mose, the prophets and the psalms".
Extra-biblical we see that Philo of Alexandria writes (De vita contemplativa 3,25) and states that besides the law and the prophecies there are other writings that can be used to perfect the believes and that are useful for the believer.
That all points into the direction that the Tora always had primacy and that N and finally K became to be regraded as 'also tora' or 'the canon of Jewish scripture' in that timeframe.
Note that this is not discussiong what exactly these books are, nor what exact form they had, that formed this 'canon'. But note the discrepancy between Septuagint, Old Testament (of various colours) and the statement on pure number of books contained in such a canon as stated by Josephus. -> That still wasn't really fixed at that time.
The earliest possible, but ultimately inconclusive statement we can use is
Whereas many great teachings have been given to us through the law and the prophets and the others that followed them,
Wisdom of Jesus Son of Sirach, RSV
This is conventionally dated at 132 BC. That date is not fixed for the text we have today, and it is not ultimately clear what "the others that followed" really means. But the context for the idea or a tripartite organisation is there.