Can't build app from source. app-lib: env variable 'modrinth_**' not defined at compile time

[FallenVEye]

Please confirm the following.

• I checked the existing issues for duplicate problems
• I have tried resolving the issue using the support portal
• I have ensured my Modrinth App installation is up to date

What version of the Modrinth App are you using?

The current main HEAD(f303395), also v0.10.23

What operating systems are you seeing the problem on?

Linux

Describe the bug

Compiling of the app-lib fails during pnpm app:dev with error:

error: environment variable `MODRINTH_API_URL` not defined at compile time
   --> packages/app-lib/src/state/cache.rs:946:21
    |
946 |                     env!("MODRINTH_API_URL"),
    |                     ^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: use `std::env::var("MODRINTH_API_URL")` to read the variable at run time

    Building [=======================> ] 799/806: tauri-plugin-fs, theseus, tauri, tauri-plugin-updater 

Running cargo build for app-lib leads to the same issue. It only compiles if i export those variables in the shell, but it doesn't work for app:dev

Steps to reproduce

1. Get the fresh repo
2. Run pnpm install (works fine)
3. Run pnpm app:dev

Expected behavior

No response

Additional context

OS: Arch Linux x86_64
node: v22.17.0
pnpm: 10.24.0
rustc: 1.88.0
Tauri: 2.7.0

[Prospector]

You need a .env file in order to setup the necessary env variables. Copy the .env.prod file to .env