Hard to add anything after Dusto, but I'll try. I think the concept here is great. There's a lot of places you could take this, whether that be the Moonlighter / Recettear route, or a more straightforward shopkeeper sim. What I'm trying to say is, this is not new territory you're entering here. The shopkeeper genre is, if not mainstream, then at least well-established.
The game itself is a good start, I'd say. As Dusto said, a bit of expansion in the book tab would be nice, and maybe that could be gameified. Games like Moonlighter and Recettear have a dungeon-crawl aspect; yours could be more research based. You could gather notes from your fellow herbalists or through trial and error about what plants work for what. I'd also say a bit more room would be nice. Three pots is a good start, but the ability to expand your shop would be pretty cool.
As far as replayability, I would say another gameplay loop would be good. Stardew Valley has the farming, but you can also fish or mine or fight monsters or romance people. The shop maintenance is a good base, but maybe expand a bit so the game isn't quite so one-and-done. I like how focused the game is on herbalism; maybe the introduction of a narrative would help us as the player learn the art of herbalism with the character. They're obviously pretty new to this since only know what one plant does. This could both expand the gameplay as well as to give people a reason to get invested.
As Dusto said, the amount of systems in here is impressive. Great job so far, and keep up the good work!