[BUG] Typst files dirty the tags list

[Batres3]

The feature implemented in #486 makes it so typst preambles can be imported from files in typst/*.md, however, typst defines variables as #let var = ..., therefore, it fills the tags with random names, since variables are referenced in math mode as #var. It would be ideal to skip these files.

[adibhanna]

Good catch, and thanks for tying it back to #486 with the reason: #let bindings and the #var references in formulas are exactly what the tag scanner was reading as hashtags.

Fixed. Notes in the preamble folder are now left out of the tag index on every runtime: the app, the zn CLI, MCP, and the self-hosted server. Tags are the only thing skipped, so a preamble keeps its excerpt, its wikilinks and its searchability, which is what #486 made preambles ordinary notes for. Tags never took part in resolving a preamble anyway (it is addressed by its title), so nothing is lost.

The folder is configurable now, because skipping it is not free. If you keep ordinary tagged notes in a folder that happens to be called typst, you would have lost those tags with no way out. So typstPreambles.folder in vault.json names the folder, Settings → Editor → Typst preamble folder edits it, and moving it moves the preamble resolution and the tag exclusion together. It is stored in the vault, so it travels with it and every runtime agrees.

Verified by driving the built app: with a typst/physics.md containing #let vec(x) = bold(x) and a formula calling #vec, the sidebar tag list went from ["grad","let","mechanics","physics","vec"] to ["mechanics","physics"], with an ordinary note's tags untouched. Renaming the folder in Settings then moved the exclusion, giving the old folder's notes their tags back.

One upgrade note: your existing vault caches note metadata in .zennotes/. That snapshot now records which preamble folder it was built under and is discarded when it disagrees, so your tag list is corrected on the first launch after updating rather than lingering until each file changes.

Fixed in 6533186, shipping in the next release. If you want it sooner you can build from the v2.26.0 branch.