As a user, I can find tree fungi by tree species

As a user, I want to find tree fungi by selecting tree species with names listed so I can identify fungi for specific species.

[ ] A dropdown or filter labeled "Tree Species" is implemented with a list of common tree species.
[ ] Selecting a species filters the fungi list to show diseases affecting that specific species.
[ ] Each fungi entry contains the name, description, and an optional photo.

OlgaOrl / Tree-Fungi-Identifier