Improve Fungal Cavern sublocation logic

[zozoens31]

Summary

• Improve sublocation detection logic for Fungal Cavern in the CRE bookmarklet
• Adds standard cheese handling for Fungal Cavern sublocations

Test plan

• Verify CRE bookmarklet correctly detects Fungal Cavern sublocations with standard cheese

🤖 Generated with Claude Code

[hymccord]

Two things:

1. I agree the sublocation logic needs to be changed since using standard cheese should not be a sublocation but you don't need to return "-". Just don't return anything. "-" is the default when the urlparam for sublocation isn't specified.
2. You also need to update the logic in a 2nd place; src/bookmarklet/bm-setup-fields.js

Basically the logic for it to be either Gemology or Not Gemology requires the user to have cavern based cheese.

Pseudo code:

if (hasCavernCheese) {
  return hasGemologyBase ? "Gemology" : "Not Gemology"
}

[hymccord]

LGTM. I'll ping Aard since he's got merge powah.