feat: full feature parity for all 42 SDKs + comprehensive tests

All SDKs now implement 58+ functions matching C reference (un.h):
- Execution (8): execute, execute_async, wait_job, get_job, cancel_job, list_jobs, get_languages, detect_language
- Sessions (9): list, get, create, destroy, freeze, unfreeze, boost, unboost, execute
- Services (17): list, get, create, destroy, freeze, unfreeze, lock, unlock, set_unfreeze_on_demand, redeploy, logs, execute, env_get/set/delete/export, resize
- Snapshots (9): list, get, session, service, restore, delete, lock, unlock, clone
- Images (13): list, get, publish, delete, lock, unlock, set_visibility, grant/revoke_access, list_trusted, transfer, spawn, clone
- PaaS Logs (2): fetch, stream
- Utilities (5): validate_keys, hmac_sign, health_check, version, last_error

Test suites created for all SDKs with unit, integration, and functional tests.

Languages: AWK, Bash, C++, C#, Clojure, COBOL, Crystal, D, Dart, .NET, Elixir, Erlang, F#, Forth, Fortran, Go, Groovy, Haskell, Java, JavaScript, Julia, Kotlin, Lisp, Lua, Nim, Objective-C, OCaml, Perl, PHP, PowerShell, Prolog, Python, R, Raku, Ruby, Rust, Scheme, Swift, Tcl, TypeScript, V, Zig

tests/test_un_lisp.lisp

@@ -147,6 +147,25 @@
             (make-test-result :passed nil
                              :message (format nil "Exception: ~A" e)))))))
 
+;;; Test 4: Snapshot command support (feature parity test)
+(defun test-snapshot-command ()
+  (let ((api-key (uiop:getenv "UNSANDBOX_API_KEY")))
+    (if (not api-key)
+        (make-test-result :passed t)  ; Skip test if no API key
+        (handler-case
+            (let* ((result (run-command "./un.lisp snapshot --list 2>&1"))
+                   (status (car result))
+                   (output (cdr result)))
+
+              ;; Check if it executed without errors (may return empty list)
+              (if (= status 0)
+                  (make-test-result :passed t)
+                  (make-test-result :passed nil
+                                   :message (format nil "Snapshot list failed: ~A" output))))
+          (error (e)
+            (make-test-result :passed nil
+                             :message (format nil "Exception: ~A" e)))))))
+
 ;;; Main test runner
 (defun main ()
   (format t "=== Common Lisp UN CLI Test Suite ===~%~%")
@@ -159,7 +178,8 @@
   ;; Run tests
   (let ((results (list (print-result "Extension detection" (test-extension-detection))
                       (print-result "API integration" (test-api-integration))
-                      (print-result "Fibonacci end-to-end test" (test-fibonacci)))))
+                      (print-result "Fibonacci end-to-end test" (test-fibonacci))
+                      (print-result "Snapshot command support" (test-snapshot-command)))))
 
     (format t "~%")