Add key subcommand to remaining 25 implementations

Complete key command across all 42 CLI implementations:
- un.go, un.v, un.fs, un.groovy (systems/JVM)
- un.dart, un_inception.c, un_deno.ts, un.ps1 (mixed)
- un.hs, un.ml, un.clj, un.scm (functional)
- un.lisp, un.erl, un.ex, un.f90 (functional/scientific)
- un.cob, un.pro, un.forth, un.raku (exotic)
- un.m, un.awk (other)
- un.js, un.ts, un.pl (fixes to existing)

All implementations now support:
- key: Validate API key and show status
- key --extend: Open browser to renew key

un.lisp

@@ -242,6 +242,14 @@
        (when public-key (format t "Public Key: ~a~%" public-key))
        (when tier (format t "Tier: ~a~%" tier))
        (when expires-at (format t "Expires: ~a~%" expires-at))
+       (let ((time-remaining (parse-json-field response "time_remaining"))
+             (rate-limit (parse-json-field response "rate_limit"))
+             (burst (parse-json-field response "burst"))
+             (concurrency (parse-json-field response "concurrency")))
+         (when time-remaining (format t "Time Remaining: ~a~%" time-remaining))
+         (when rate-limit (format t "Rate Limit: ~a~%" rate-limit))
+         (when burst (format t "Burst: ~a~%" burst))
+         (when concurrency (format t "Concurrency: ~a~%" concurrency)))
        (when extend-flag
          (if public-key
              (let ((extend-url (format nil "~a/keys/extend?pk=~a" *portal-base* public-key)))