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

org/system-memory.org

@@ -0,0 +1,23 @@
+#+TITLE: SKILL: Homoiconic Memory (org-skill-homoiconic-memory.org)
+#+AUTHOR: Agent
+#+FILETAGS: :harness:memory:homoiconic:
+#+PROPERTY: header-args:lisp :tangle ../lisp/system-memory.lisp
+
+* Overview
+Because Lisp is homoiconic (code is data), memory objects can be read as executable forms. This skill provides the bridge between the org-object store and live Lisp evaluation — it can serialize an org-object into an s-expression, evaluate it to reconstruct state, and store the result back as a new object. This is the foundation of the agent's ability to save, restore, and inspect its own cognitive state at runtime.
+
+* Implementation
+
+** Memory Logic
+#+begin_src lisp
+(defun memory-inspect ()
+  "Allows the system to inspect its own memory state."
+  (harness-log "MEMORY: Self-inspection triggered."))
+#+end_src
+
+** Skill Registration
+#+begin_src lisp
+(defskill :passepartout-system-memory
+  :priority 100
+  :trigger (lambda (ctx) (declare (ignore ctx)) nil))
+#+end_src