WASM build fails due to missing main symbol when linking C libraries

[roninjin10]

Problem

The WASM build (zig build wasm) fails with:

wasm-ld: undefined symbol: main

This happens because:

1. The primitives dependency includes C libraries (BLST, C-KZG, BN254)
2. These require linking with libc (-lc)
3. WASI libc expects a main function entry point
4. Even with entry = .disabled and -fno-entry, the linker still requires main

Current Workaround

Removed WASM from the default zig build step (commit 2d2119a). The WASM build is now only triggered explicitly via zig build wasm, but it still fails.

Potential Solutions

1. Add a stub main function - Export a no-op main in src/root_c.zig when targeting WASI
2. Use freestanding target - Switch from wasm32-wasi to wasm32-freestanding, but this may break C library compatibility
3. Conditional C library linking - Only link crypto libraries when not targeting WASM (would reduce WASM functionality)
4. Custom WASI reactor entry - Use _initialize instead of main for WASI reactor-style modules

References

• WASI Application ABI - Reactors vs Commands
• Zig WASI support