feat: add DeepSeek and NVIDIA NIM providers

- Add deepseek and nvidia entries to gateway-provider config

- Add DEEPSEEK_API_KEY and NVIDIA_API_KEY to .env.example

- Add deepseek and nvidia to doctor's LLM provider check

- Fix remaining harness-log → log-message reference

lisp/gateway-llm.lisp

@@ -0,0 +1,43 @@
+(defun gateway-llm-request (&key prompt system-prompt (provider :ollama) model)
+  "Central dispatcher for LLM requests."
+  (let ((backend (gethash provider *probabilistic-backends*)))
+    (if backend
+        (handler-case
+            (funcall backend prompt system-prompt :model model)
+          (error (c)
+            (list :status :error :message (format nil "~a Failure: ~a" provider c))))
+        (list :status :error :message (format nil "Provider ~a not registered" provider)))))
+
+(defskill :passepartout-gateway-llm
+  :priority 100
+  :trigger (lambda (ctx) (getf ctx :user-input))
+  :deterministic (lambda (action ctx) (declare (ignore ctx)) action))
+
+(eval-when (:compile-toplevel :load-toplevel :execute)
+  (ql:quickload :fiveam :silent t))
+
+(defpackage :passepartout-llm-gateway-tests
+  (:use :cl :passepartout)
+  (:export #:llm-gateway-suite))
+
+(in-package :passepartout-llm-gateway-tests)
+
+(fiveam:def-suite llm-gateway-suite :description "Tests for the LLM Gateway skill")
+(fiveam:in-suite llm-gateway-suite)
+
+(fiveam:test test-llm-gateway-timeout
+  "Tier 2 Chaos: Verify that LLM Gateway handles connection failures gracefully."
+  (let ((old-host (uiop:getenv "OLLAMA_HOST")))
+    (unwind-protect
+         (progn
+           (setf (uiop:getenv "OLLAMA_HOST") "localhost:1")
+           (let ((fn (or (find-symbol "EXECUTE-LLM-REQUEST" :passepartout.gateway-llm)
+                         (find-symbol "EXECUTE-LLM-REQUEST" :passepartout))))
+             (if fn
+                 (let ((result (funcall fn :prompt "hello" :provider :ollama)))
+                   (fiveam:is (eq (getf result :status) :error))
+                   (fiveam:is (uiop:string-prefix-p "Ollama Failure" (getf result :message))))
+                 (fiveam:fail "Could not find EXECUTE-LLM-REQUEST symbol"))))
+      (if old-host
+          (setf (uiop:getenv "OLLAMA_HOST") old-host)
+          (sb-posix:unsetenv "OLLAMA_HOST")))))