feat(Nushell): using 'whoami' to obtain username

nushell/modules/pj_prompt.nu

@@ -146,8 +146,17 @@ def _pj_palette [] {
     ($env.PJ_PROMPT_PALETTE? | default (_pj_palette_default))
 }
 
+def _pj_detect_user [] {
+    let name = (try { whoami } catch { "" } | into string | str trim)
+    if ($name != "") {
+        return $name
+    }
+
+    ($env.USER? | default ($env.USERNAME? | default "user"))
+}
+
 def _pj_runtime_default [] {
-    let user = ($env.USER? | default ($env.USERNAME? | default "user"))
+    let user = (_pj_detect_user)
     let host = (sys host | get hostname? | default "")
     {
         user: $user