fix: address PR review feedback

- buffer2hex: normalize JSON-parsed buffer input (number[] or {type,data})
- getSupportedRFRegions: use readonly in outgoing type, remove unnecessary spread
- getCCs: simplify with Object.fromEntries

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: raman325

src/lib/controller/message_handler.ts

@@ -735,7 +735,7 @@ export class ControllerMessageHandler implements MessageHandler {
         const regions = this.driver.controller.getSupportedRFRegions(
           message.filterSubsets,
         );
-        return { regions: regions ? [...regions] : undefined };
+        return { regions: regions ?? undefined };
       }
       default: {
         throw new UnknownCommandError(command);

src/lib/controller/outgoing_message.ts

@@ -196,6 +196,6 @@ export interface ControllerResultTypes {
   };
   // RF region info
   [ControllerCommand.getSupportedRFRegions]: {
-    regions: RFRegion[] | undefined;
+    regions: readonly RFRegion[] | undefined;
   };
 }

src/lib/endpoint/message_handler.ts

@@ -112,13 +112,8 @@ export class EndpointMessageHandler implements MessageHandler {
         return getRawConfigParameterValue(message, endpoint);
       }
       case EndpointCommand.getCCs: {
-        const result: EndpointResultTypes[EndpointCommand.getCCs] = {
-          commandClasses: {},
-        };
-        for (const [ccId, info] of endpoint.getCCs()) {
-          result.commandClasses[ccId] = info;
-        }
-        return result;
+        const commandClasses = Object.fromEntries(endpoint.getCCs());
+        return { commandClasses };
       }
       case EndpointCommand.maySupportBasicCC: {
         const maySupport = endpoint.maySupportBasicCC();

src/lib/utils/incoming_message.ts

@@ -28,7 +28,7 @@ export interface IncomingCommandUtilsFormatId extends IncomingCommandUtilsBase {
 
 export interface IncomingCommandUtilsBuffer2hex extends IncomingCommandUtilsBase {
   command: UtilsCommand.buffer2hex;
-  buffer: Buffer<ArrayBuffer>; // Parsed buffers own their data
+  buffer: number[] | { type: "Buffer"; data: number[] };
   uppercase: boolean;
 }
 

src/lib/utils/message_handler.ts

@@ -36,7 +36,9 @@ export class UtilsMessageHandler implements MessageHandler {
         return { id };
       }
       case UtilsCommand.buffer2hex: {
-        const hex = buffer2hex(message.buffer, message.uppercase);
+        const raw = message.buffer;
+        const bytes = Array.isArray(raw) ? raw : raw.data;
+        const hex = buffer2hex(Uint8Array.from(bytes), message.uppercase);
         return { hex };
       }
       case UtilsCommand.getEnumMemberName: {