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/security-policy.org

@@ -0,0 +1,38 @@
+#+TITLE: SKILL: Policy (org-skill-policy.org)
+#+AUTHOR: Agent
+#+FILETAGS: :system:policy:constitutional:
+#+PROPERTY: header-args:lisp :tangle ../lisp/security-policy.lisp
+
+* Architectural Intent: The Constitutional Layer
+
+The Policy skill encodes the non-negotiable values of Passepartout. Every action the agent proposes must pass through this gate. If the action lacks justification, it is blocked — not because it's dangerous, but because it's opaque.
+
+This is the "Radical Transparency" invariant in practice. The agent must explain *why* it wants to do something, not just *what* it wants to do. An action with ~:explanation "Because I said so"~ is rejected. An action with ~:explanation "The user asked me to read their TODO list and summarize it"~ passes.
+
+The Policy skill is intentionally simple. It has one job: ensure every action has a meaningful explanation. Other security concerns (secret scanning, path blocking, network exfiltration) are handled by the Bouncer. The Policy is about values, not threats.
+
+* Implementation
+
+** Policy Logic (policy-compliance-check)
+#+begin_src lisp
+(defun policy-compliance-check (action context)
+  "Enforces constitutional invariants on proposed actions."
+  (declare (ignore context))
+  (let* ((payload (proto-get action :payload))
+         (explanation (proto-get payload :explanation)))
+    (if (and explanation (stringp explanation) (> (length explanation) 10))
+        action
+        (progn
+          (harness-log "POLICY VIOLATION: Action lacks sufficient explanation.")
+          (list :type :LOG
+                :payload (list :level :warn
+                              :text "Action blocked: Missing or insufficient :explanation. Please justify your reasoning."))))))
+#+end_src
+
+** Skill Registration
+#+begin_src lisp
+(defskill :passepartout-security-policy
+  :priority 500
+  :trigger (lambda (ctx) (declare (ignore ctx)) t)
+  :deterministic #'policy-compliance-check)
+#+end_src