v0.7.2: tool execution hardening — TDD

Per-tool timeouts: shell=300s, search-files=30s, eval-form=10s,
unknown=120s default. Write verification: after write-file,
reads back content and compares, logs mismatches.

- core-act: *tool-timeouts* hash, tool-timeout, verify-write
- programming-tools: verify-write call in write-file body
- Act tests: +3 (timeout shell, timeout unknown, verify match)
- Core: 84/84

lisp/programming-tools.lisp

@@ -101,10 +101,11 @@
                    (content (getf args :content)))
               (unless (and filepath content)
                 (return (list :status :error :message "write-file requires :filepath and :content")))
-              (handler-case
-                  (progn
-                    (tools-write-file filepath content)
-                    (list :status :success
+               (handler-case
+                   (progn
+                     (tools-write-file filepath content)
+                     (verify-write filepath content)
+                     (list :status :success
                           :content (format nil "Written ~d bytes to ~a" (length content) filepath)))
                 (error (c) (list :status :error :message (format nil "~a" c))))))))