fix(utils): use || instead of ?? for CLAUDE_PATH

The previous null‑ish coalescing treated empty strings as a valid value, which could result in an invalid path. Switching to logical OR keeps the precedence (config > env) but now falls back to the default `claude`

src/utils/codeCommand.ts

@@ -52,7 +52,7 @@ export async function executeCodeCommand(args: string[] = []) {
   incrementReferenceCount();
 
   // Execute claude command
-  const claudePath = config?.CLAUDE_PATH ?? process.env.CLAUDE_PATH ?? "claude";
+  const claudePath = config?.CLAUDE_PATH || process.env.CLAUDE_PATH || "claude";
 
   // Properly join arguments to preserve spaces in quotes
   // Wrap each argument in double quotes to preserve single and double quotes inside arguments