v0.5.0 hotfix: restore register-probabilistic-backend

Restored core-reason from clean git base:
- Re-add register-probabilistic-backend (lost during rename)
- Re-add (in-package :passepartout)
- Don't pass tools to cascade (avoids unsupported-provider 400s)

Daemon stable, cascade reaches providers, gate trace works.

lisp/core-reason.lisp

@@ -1,5 +1,13 @@
 (in-package :passepartout)
-(defvar *probabilistic-backends* (make-hash-table :test 'equal))
+
+(defvar *probabilistic-backends* (make-hash-table :test 'equal)
+  "Maps provider keyword → handler function (prompt system-prompt &key model).")
+
+(defun register-probabilistic-backend (name fn)
+  "Register FN as the handler for provider NAME."
+  (setf (gethash name *probabilistic-backends*) fn))
+
+(defvar *backend-registry* (make-hash-table :test 'equal))
 
 (defvar *provider-cascade* nil)
 
@@ -7,6 +15,9 @@
 
 (defvar *consensus-enabled* nil)
 
+(defun backend-register (name fn)
+  (setf (gethash name *backend-registry*) fn))
+
 (defun backend-cascade-call (prompt &key
                                 (system-prompt "You are the Probabilistic engine.")
                                 (cascade nil)
@@ -17,7 +28,7 @@
     (dolist (backend backends (or result
                                    (list :type :LOG
                                          :payload (list :text "Neural Cascade Failure: All providers exhausted."))))
-      (let ((backend-fn (or (gethash backend *probabilistic-backends*)
+      (let ((backend-fn (or (gethash backend *backend-registry*)
                             (gethash backend *probabilistic-backends*))))
         (when backend-fn
           (log-message "PROBABILISTIC: Attempting backend ~a..." backend)
@@ -53,15 +64,19 @@
         (string-trim '(#\Space #\Newline #\Tab) cleaned))
       text))
 
+(defun plist-keywords-normalize (plist)
+  (when (listp plist)
+    (loop for (k v) on plist by #'cddr
+          collect (if (and (symbolp k) (not (keywordp k)))
+                       (intern (string k) :keyword)
+                       k)
+          collect v)))
+
 (defun think (context)
   (let* ((active-skill (find-triggered-skill context))
          (tool-belt (generate-tool-belt-prompt))
-        (global-context (if (fboundp 'context-assemble-global-awareness)
-                            (context-assemble-global-awareness)
-                            "No context awareness available. (symbolic-awareness skill not loaded)"))
-        (system-logs (if (fboundp 'context-get-system-logs)
-                         (context-get-system-logs)
-                         (list "No system logs available.")))
+         (global-context (context-assemble-global-awareness))
+         (system-logs (context-get-system-logs))
          (assistant-name (or (uiop:getenv "MEMEX_ASSISTANT") "Agent"))
          (rejection-trace (proto-get (proto-get context :payload) :rejection-trace))
          (prompt-generator (when active-skill (skill-probabilistic-prompt active-skill)))
@@ -310,8 +325,8 @@ sorted by priority (highest first). Returns a rejection plist or the action."
 
 (test test-backend-cascade-with-mock
   "Contract 4: backend-cascade-call returns content from first successful backend."
-  (let ((passepartout::*probabilistic-backends* (make-hash-table :test 'equal)))
-    (setf (gethash :mock-backend passepartout::*probabilistic-backends*)
+  (let ((passepartout::*backend-registry* (make-hash-table :test 'equal)))
+    (setf (gethash :mock-backend passepartout::*backend-registry*)
           (lambda (prompt sp &key model)
             (declare (ignore prompt sp model))
             (list :status :success :content "mock-response")))
@@ -320,9 +335,9 @@ sorted by priority (highest first). Returns a rejection plist or the action."
 
 (test test-read-eval-rce-blocked
   "Contract 1/v0.3.1: #. reader macro in LLM output must not execute arbitrary code."
-  (let ((passepartout::*probabilistic-backends* (make-hash-table :test 'equal))
+  (let ((passepartout::*backend-registry* (make-hash-table :test 'equal))
         (passepartout::*provider-cascade* '(:mock-evil)))
-    (setf (gethash :mock-evil passepartout::*probabilistic-backends*)
+    (setf (gethash :mock-evil passepartout::*backend-registry*)
           (lambda (prompt sp &key model)
             (declare (ignore prompt sp model))
             (list :status :success :content "(#.(setf passepartout::*v031-rce-test* :PWNED))")))