fix: Use Nightly toolchain + build-std for MIPS MUSL

.github/workflows/build-mips.yml

@@ -16,9 +16,10 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Install Rust
-      uses: dtolnay/rust-toolchain@stable
+      uses: dtolnay/rust-toolchain@nightly
       with:
         targets: wasm32-unknown-unknown
+        components: rust-src
 
     - name: Install Trunk
       uses: jetli/trunk-action@v0.5.0
@@ -35,9 +36,11 @@ jobs:
       run: cargo install cross
 
     - name: Build Backend (MIPS)
+      env:
+        RUSTUP_TOOLCHAIN: nightly
       run: |
         cd backend
-        cross build --target mips-unknown-linux-musl --release
+        cross build --target mips-unknown-linux-musl --release -Z build-std=std,panic_abort
 
     - name: Upload Binary
       uses: actions/upload-artifact@v4