docs: clarify profile resolution logic with detailed comments

Explains how profile resolution works:
- No --profile: uses Zod default (readAuthConfigCurrentProfileName)
- With --profile: trims whitespace, falls back to current if empty
- Current profile defaults to 'default' when no config exists

Author: hongkongkiwi

packages/cli-v3/src/commands/whoami.ts

@@ -74,6 +74,9 @@ export async function whoAmI(
   embedded: boolean = false,
   silent: boolean = false
 ): Promise<WhoAmIResult> {
+  // When no --profile is passed, Zod schema defaults to readAuthConfigCurrentProfileName()
+  // which returns the current profile from config or "default" if none exists.
+  // If --profile is passed, we trim whitespace and fallback to current profile if empty.
   const profileToUse = options?.profile?.trim() || readAuthConfigCurrentProfileName();
 
   if (!embedded) {