feat: Context Manager skill + org-object→memory-object fix

- system-context-manager (new skill): stack-based project focusing with
  push-context/pop-context, path resolution relative to base path, and
  scope-aware memory queries via context-scoped-query.
- core-memory: add :scope slot to memory-object struct (default :memex).
- core-memory: ingest-ast accepts &key (scope :memex), propagates to children.
- core-context: context-query accepts :scope parameter for filtering.
- DEFECT FIX: renamed org-object-* accessors to memory-object-*
  across core-context, security-dispatcher, tests, and defpackage exports.
  The struct was renamed but accessor references were never updated —
  the code referenced nonexistent functions.

lisp/security-dispatcher.lisp

@@ -285,16 +285,16 @@ privacy tags, privacy text, shell safety, network exfil, high-impact approval."
   (let ((approved-nodes (list-objects-with-attribute :TODO "APPROVED"))
         (found-any nil))
     (dolist (node approved-nodes)
-      (let* ((attrs (org-object-attributes node))
+      (let* ((attrs (memory-object-attributes node))
              (tags (getf attrs :TAGS))
              (action-str (getf attrs :ACTION)))
         (when (and (member "FLIGHT_PLAN" tags :test #'string-equal) action-str)
-          (log-message "BOUNCER: Found approved flight plan '~a'. Re-injecting..." (org-object-id node))
+          (log-message "BOUNCER: Found approved flight plan '~a'. Re-injecting..." (memory-object-id node))
           (let ((action (ignore-errors (read-from-string action-str))))
             (when action
               (setf (getf action :approved) t)
               (inject-stimulus action)
-              (setf (getf (org-object-attributes node) :TODO) "DONE")
+              (setf (getf (memory-object-attributes node) :TODO) "DONE")
               (setq found-any t))))))
     found-any))