v0.7.2: safe-tool read-only allowlist — TDD

Read-only cognitive tools auto-pass dispatcher-check unconditionally.
Added :read-only-p slot to cognitive-tool struct, :read-only-p keyword
to def-cognitive-tool macro, tool-read-only-p registry lookup.

- core-package: struct + macro + tool-read-only-p function
- security-dispatcher: early auto-pass in dispatcher-check, 2 new tests
- programming-tools: 7 tools marked :read-only-p t (search-files,
  find-files, read-file, list-directory, eval-form, run-tests,
  org-find-headline)
- Dispatcher: 38/38

lisp/core-package.lisp

@@ -70,10 +70,11 @@
     #:hitl-approve
     #:hitl-deny
     #:hitl-handle-message
-    #:dispatcher-check-secret-path
-    #:dispatcher-check-shell-safety
-    #:dispatcher-check-privacy-tags
-    #:dispatcher-check-network-exfil
+   #:dispatcher-check-secret-path
+   #:dispatcher-check-shell-safety
+   #:dispatcher-check-privacy-tags
+   #:dispatcher-check-network-exfil
+   #:dispatcher-check
     #:dispatcher-gate
     #:wildcard-match
     #:actuator-initialize
@@ -142,6 +143,7 @@
    #:cognitive-tool-parameters
    #:cognitive-tool-guard
    #:cognitive-tool-body
+   #:tool-read-only-p
    #:register-probabilistic-backend
    #:*probabilistic-backends*
    #:*provider-cascade*
@@ -216,16 +218,18 @@
   description
   parameters
   guard
-  body)
+  body
+  read-only-p)
 
-(defmacro def-cognitive-tool (name description parameters &key guard body)
+(defmacro def-cognitive-tool (name description parameters &key guard body read-only-p)
   "Registers a cognitive tool. PARAMETERS is a list of plists, one per parameter."
   `(setf (gethash (string-downcase (string ',name)) *cognitive-tool-registry*)
          (make-cognitive-tool :name (string-downcase (string ',name))
                               :description ,description
                               :parameters ',parameters
                               :guard ,guard
-                              :body ,body)))
+                              :body ,body
+                              :read-only-p ,read-only-p)))
 
 (defun cognitive-tool-prompt ()
   "Serialises all registered tools into a prompt string for the LLM."
@@ -246,6 +250,12 @@
 (defun generate-tool-belt-prompt ()
   (cognitive-tool-prompt))
 
+(defun tool-read-only-p (name)
+  "Returns T if the named cognitive tool is read-only, NIL otherwise."
+  (let ((tool (gethash (string-downcase (string name)) *cognitive-tool-registry*)))
+    (when tool
+      (cognitive-tool-read-only-p tool))))
+
 (defun log-message (msg &rest args)
   "Centralized, thread-safe logging for the harness."
   (let ((formatted-msg (apply #'format nil msg args)))