v0.4.1: native embedding CFFI — full pipeline working, daemon-wired, HITL bug fixed

- Native backend returns 768-dim vectors via llama.cpp / C wrapper (/usr/local/lib/libllama_wrap.so)
- Wired :native into embed-object dispatch and exported from passepartout package
- Model preloads at daemon startup with EMBEDDING_PROVIDER=native (~30s)
- Lazy loading via *embedding-backend* :native also works (first call ~45s)
- C wrapper bridges CFFI pointer params to llama.cpp struct-by-value API
- Correct struct layouts: llama_model_params(72B), llama_context_params(136B), llama_batch(56B)
- BERT pooling: llama_get_embeddings_seq, llama_tokenize takes vocab* not model*
- FiveAM tests pass: dimensions, self-similarity, semantic ranking
- Fixed pre-existing HITL crash: boundp guard for *hitl-pending* in core-loop-act
- Lazy load guard prevents double-load of native file in embedding-native-ensure-loaded
- ROADMAP: v0.4.0 items marked DONE, v0.4.1 native embedding updated with actual implementation

lisp/system-model-embedding.lisp

@@ -1,7 +1,7 @@
 (in-package :passepartout)
 
 (defvar *embedding-provider* :trigram
-  "Active embedding provider: :trigram, :sha256, :local, :openai.")
+  "Active embedding provider: :trigram, :sha256, :local, :openai, :native.")
 
 (defvar *embedding-queue* nil
   "Queue of text objects awaiting embedding.")
@@ -85,10 +85,14 @@ Pure Lisp, zero external dependencies, works fully offline."
   "Embed a single text string using the active backend."
   (let* ((selected (or *embedding-backend* *embedding-provider* :trigram))
          (backend (case selected
-                     (:local #'embedding-backend-local)
-                     (:openai #'embedding-backend-openai)
-                     (:sha256 #'embedding-backend-sha256)
-                     (t #'embedding-backend-trigram))))
+                    (:local #'embedding-backend-local)
+                    (:openai #'embedding-backend-openai)
+                    (:native
+                     (unless (fboundp 'embedding-backend-native)
+                       (embedding-native-ensure-loaded))
+                     #'embedding-backend-native)
+                    (:sha256 #'embedding-backend-sha256)
+                    (t #'embedding-backend-trigram))))
     (if backend
         (progn
           (log-message "EMBEDDING: Provider ~a, backend=~a" selected backend)
@@ -126,6 +130,34 @@ Pure Lisp, zero external dependencies, works fully offline."
       (setf *embedding-provider* kw)
       (log-message "EMBEDDING: Set provider to ~a from EMBEDDING_PROVIDER env" kw))))
 
+(defun embedding-native-ensure-loaded ()
+  "Lazy-load the native CFFI backend. First call blocks ~30s for model init."
+  (when (fboundp 'embedding-backend-native)
+    (return-from embedding-native-ensure-loaded t))
+  (let* ((data-dir (uiop:ensure-directory-pathname
+                    (or (uiop:getenv "PASSEPARTOUT_DATA_DIR")
+                        (namestring (merge-pathnames ".local/share/passepartout/"
+                                                    (user-homedir-pathname))))))
+         (native-file (merge-pathnames "lisp/system-model-embedding-native.lisp" data-dir)))
+    (handler-case
+        (progn
+          (load native-file :verbose nil :print nil)
+          (log-message "EMBEDDING: Native backend loaded from ~a" native-file))
+      (error (c)
+        (error "Failed to load native embedding backend (~a): ~a" native-file c)))))
+
+;; Preload native model if configured at startup
+(when (eq *embedding-provider* :native)
+  (log-message "EMBEDDING: Native provider configured, preloading model...")
+  (embedding-native-ensure-loaded)
+  (handler-case
+      (progn
+        (embedding-native-load-model)
+        (log-message "EMBEDDING: Native model preloaded (~d dims)"
+                     (embedding-native-get-dim)))
+    (error (c)
+      (log-message "EMBEDDING: Preload deferred: ~a (will retry on first call)" c))))
+
 (log-message "EMBEDDING: Gateway loaded with provider ~a" *embedding-provider*)
 
 (defun mark-vector-stale (id &optional content)