fix: use RIG_VFO_NONE for getLevel/setLevel to fix ICOM serial rigs

ICOM rigs (e.g. IC-705) fail when rig_get_level is called with
RIG_VFO_CURR because Hamlib's ICOM backend internally calls
icom_set_vfo which returns "unsupported VFO" for CI-V protocol.

Using RIG_VFO_NONE (0) tells Hamlib to operate on the current VFO
without attempting a VFO switch, which is the correct behavior for
meter reading operations.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: boybook

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hamlib",
-  "version": "0.2.2",
+  "version": "0.2.3",
   "description": "Node.js wrapper for hamlib radio control library",
   "main": "index.js",
   "module": "lib/index.mjs",

src/hamlib.cpp

@@ -280,7 +280,7 @@ class SetLevelAsyncWorker : public HamLibAsyncWorker {
     void Execute() override {
         CHECK_RIG_VALID();
 
-        result_code_ = shim_rig_set_level_f(hamlib_instance_->my_rig, SHIM_RIG_VFO_CURR, level_type_, value_);
+        result_code_ = shim_rig_set_level_f(hamlib_instance_->my_rig, SHIM_RIG_VFO_NONE, level_type_, value_);
         if (result_code_ != SHIM_RIG_OK) {
             error_message_ = shim_rigerror(result_code_);
         }
@@ -313,7 +313,9 @@ class GetLevelAsyncWorker : public HamLibAsyncWorker {
     void Execute() override {
         CHECK_RIG_VALID();
 
-        result_code_ = shim_rig_get_level_f(hamlib_instance_->my_rig, SHIM_RIG_VFO_CURR, level_type_, &value_);
+        // Use RIG_VFO_NONE to avoid unnecessary VFO switching that fails on
+        // ICOM rigs (e.g. IC-705) where icom_set_vfo returns "unsupported VFO"
+        result_code_ = shim_rig_get_level_f(hamlib_instance_->my_rig, SHIM_RIG_VFO_NONE, level_type_, &value_);
         if (result_code_ != SHIM_RIG_OK) {
             error_message_ = shim_rigerror(result_code_);
         }