feat: Add SE050 hardware RNG integration

- Added system RNG fallback using /dev/urandom
- Created se050_wireguard_se050_rng.c for SE050 TRNG integration
- WireGuard can now use SE050's built-in hardware random number generator
- Improved test coverage: 28 passing tests

Usage for SE050 RNG:

For standalone (no SE050):

CMakeLists.txt

@@ -27,6 +27,7 @@ set(SOURCES
     src/se050_wireguard_proto.c
     src/se050_tai64n_hw.c
     src/se050_wireguard.c
+    src/se050_wireguard_se050_rng.c
 )
 
 # Create library