This isn't an answer but this archetype exists in many Taoist tails, both old and new. The Taoist sage in most stories tends to be an old man sporting a long beard who says few things.

It is likely that the archetype precedes the Shiji, perhaps by hundreds of years, but it is from the Shiji that we may say the archetype was well and fully established. It comes out frequently in tales of wise and hidden scholars, recruited to deal with some crisis or another by the local ruler. These scholars were not part of any designated ideology, but instead were a pure wise master archetype. Some confucian and/or Daoist (or some other early Han ist) ideals can be inferred from them, but in those that I have read, no ideology was dominant in their characterizations.
So, the answer is, at latest around 100 BCE.