Add TUN kernel module for Mycelium networking

- Added tun.ko module installation to scripts/install-firmware-minimal.sh
- Essential for Mycelium's tunnel networking functionality
- Module will be installed alongside other network drivers during build

scripts/install-firmware-minimal.sh

@@ -130,6 +130,9 @@ if [ -d "$KERNEL_BUILD_DIR" ]; then
     # Filesystem drivers (overlay for container support)
     find "$KERNEL_BUILD_DIR" -name "overlay.ko" -exec cp {} "$MODULES_DIR/kernel/fs/" \; 2>/dev/null || true
     
+    # Tunnel drivers (tun for Mycelium networking)
+    find "$KERNEL_BUILD_DIR" -name "tun.ko" -exec cp {} "$MODULES_DIR/kernel/drivers/net/" \; 2>/dev/null || true
+    
     # Create modules directories
     mkdir -p "$MODULES_DIR/kernel/drivers"
     mkdir -p "$MODULES_DIR/kernel/fs"