rename gateway-* → system-model-* + gateway-messaging, de-ollama, add system-model-explorer

- Rename gateway-provider → system-model-provider (generic :local provider, no hardcoded ollama)
- Rename gateway-llm → system-model (model-request dispatcher)
- Rename system-embedding-gateway → system-model-embedding
- Rename gateway-manager → gateway-messaging (public api renamed to messaging-*)
- Add system-model-explorer (model discovery via OpenRouter API, cached, per-slot recommendations)
- Fix skill loader export: replace prefix-matching with fbound/boundp-based export (20 skills now export)
- Add model-router to skill-loader exclusion list (loaded via CLI)
- De-ollama: remove hardcoded assumed-available patterns from provider pipeline
- Default cascade: cloud-only (openrouter, openai, groq, gemini, deepseek, nvidia, anthropic)
- Env example: add LOCAL_BASE_URL, fix cascade order
- All org files updated with architectural prose (literate programming)

lisp/system-model-explorer.lisp

@@ -0,0 +1,63 @@
+(in-package :passepartout)
+
+(defvar *model-cache* (make-hash-table :test 'equal)
+  "Cache: provider keyword -> (timestamp . model-list)")
+
+(defvar *model-cache-ttl* 300
+  "Cache TTL in seconds (default 5 min)")
+
+(defun model-explorer-fetch-openrouter ()
+  "Query OpenRouter /api/v1/models and return parsed model list."
+  (handler-case
+      (let* ((raw (dex:get "https://openrouter.ai/api/v1/models" :connect-timeout 10 :read-timeout 20))
+             (json (cl-json:decode-json-from-string raw))
+             (data (cdr (assoc :data json))))
+        (mapcar (lambda (m)
+                  (let ((pricing (cdr (assoc :pricing m))))
+                    (list :id (cdr (assoc :id m))
+                          :name (cdr (assoc :name m))
+                          :context (cdr (assoc :context_length m))
+                          :free (and pricing
+                                     (string= "0" (cdr (assoc :prompt pricing)))
+                                     (string= "0" (cdr (assoc :completion pricing)))))))
+                data))
+    (error (c)
+      (log-message "MODEL-EXPLORER: OpenRouter API error: ~a" c)
+      nil)))
+
+(defun model-explorer-fetch (provider)
+  "Fetch available models for PROVIDER. Returns list of (:id :name :context :free) plists."
+  (let ((cached (gethash provider *model-cache*)))
+    (when (and cached (< (- (get-universal-time) (car cached)) *model-cache-ttl*))
+      (return-from model-explorer-fetch (cdr cached))))
+  (let ((models (case provider
+                  (:openrouter (model-explorer-fetch-openrouter))
+                  (t nil))))
+    (when models
+      (setf (gethash provider *model-cache*)
+            (cons (get-universal-time) models)))
+    models))
+
+(defun model-explorer-list-free ()
+  "Return all free models from cache or fetch."
+  (remove-if-not (lambda (m) (getf m :free)) (model-explorer-fetch :openrouter)))
+
+(defun model-explorer-recommend (slot)
+  "Return recommended models for SLOT (:code, :chat, :plan, :background)."
+  (case slot
+    (:code
+     '((:id "qwen/qwen3-coder:free" :name "Qwen3 Coder 480B" :context 262000 :free t :note "Top-tier code MoE, 35B active")
+       (:id "poolside/laguna-m.1:free" :name "Laguna M.1" :context 131072 :free t :note "Flagship coding agent")
+       (:id "openai/gpt-oss-120b:free" :name "gpt-oss-120b" :context 131072 :free t :note "117B MoE open-weight coding")))
+    (:plan
+     '((:id "openrouter/owl-alpha" :name "Owl Alpha" :context 1048756 :free t :note "Agentic, tool use, reasoning")
+       (:id "nousresearch/hermes-3-llama-3.1-405b:free" :name "Hermes 3 405B" :context 131072 :free t :note "405B generalist, strong planning")
+       (:id "minimax/minimax-m2.5:free" :name "MiniMax M2.5" :context 196608 :free t :note "SOTA productivity, long context")))
+    (:chat
+     '((:id "meta-llama/llama-3.3-70b-instruct:free" :name "Llama 3.3 70B" :context 65536 :free t :note "Strong multilingual generalist")
+       (:id "google/gemma-4-31b-it:free" :name "Gemma 4 31B" :context 262144 :free t :note "Dense 31B, thinking mode, long context")
+       (:id "mistralai/mistral-nemo:free" :name "Mistral Nemo" :context 32768 :free t :note "Fast, good for casual conversation")))
+    (:background
+     '((:id "meta-llama/llama-3.2-3b-instruct:free" :name "Llama 3.2 3B" :context 131072 :free t :note "Small, fast, efficient")
+       (:id "liquid/lfm-2.5-1.2b-instruct:free" :name "LFM 2.5 1.2B" :context 32768 :free t :note "Ultra-compact, edge-ready")))
+    (t '((:id "meta-llama/llama-3.3-70b-instruct:free" :name "Llama 3.3 70B" :context 65536 :free t :note "Safe fallback")))))