handoff: symbolic identity file — TDD

Agent identity loaded from ~/memex/IDENTITY.org at skill startup.
Injected into system prompt IDENTITY section between assistant name
and reflection feedback. fboundp-guarded in think().

- symbolic-identity.lisp: load-identity-file, agent-identity (skill)
- token-economics: prompt-prefix-cached +identity-content param
- core-reason: identity-content binding in think(), both code paths
- Identity: 6/6  Token-econ: 10/10 new  Core: 65/65
  TUI View: 28/28  TUI Main: 70/70  Total: 179/179

lisp/symbolic-identity.lisp

@@ -0,0 +1,92 @@
+(in-package :passepartout)
+
+(defvar *agent-identity* ""
+  "Identity text loaded from ~/memex/IDENTITY.org at startup.
+
+This variable holds the contents of the user's identity file.
+Loaded by `load-identity-file` at daemon/skill initialization,
+called from `agent-identity` for system prompt injection.
+
+The file is user-editable and persists across restarts.
+If the file is missing or empty, this variable remains \"\".")
+
+(defun load-identity-file (&optional (path nil path-p))
+  "Load agent identity from an org file.
+
+Reads the identity text file and caches it in
+`*agent-identity*`.  If PATH is not provided, defaults to
+`~/memex/IDENTITY.org`.
+
+Returns the file content string on success, or NIL if the file
+does not exist or cannot be read."
+  (let* ((file-path (if path-p
+                        (uiop:ensure-pathname path :ensure-absolute t)
+                        (merge-pathnames "memex/IDENTITY.org"
+                                         (user-homedir-pathname)))))
+    (when (uiop:file-exists-p file-path)
+      (handler-case
+          (let ((content (uiop:read-file-string file-path)))
+            (setf *agent-identity* content)
+            content)
+        (error () nil)))))
+
+(defun agent-identity ()
+  "Return the currently loaded agent identity string."
+  (or *agent-identity* ""))
+
+;; Auto-load identity at skill init
+(load-identity-file)
+
+(defpackage :passepartout-identity-tests
+  (:use :common-lisp :fiveam :passepartout)
+  (:export :identity-suite))
+
+(in-package :passepartout-identity-tests)
+
+(def-suite identity-suite
+    :description "Agent identity loading and caching")
+(in-suite identity-suite)
+
+(test test-load-identity-file-returns-content
+  "Contract 1: load-identity-file reads an existing file, returns content."
+  (let* ((path "/tmp/memex-test-identity.org")
+         (content "### Personality
+- Friendly
+- Concise"))
+    (with-open-file (f path :direction :output :if-exists :supersede)
+      (write-string content f))
+    (unwind-protect
+         (let ((result (passepartout::load-identity-file path)))
+           (is (stringp result))
+           (is (search "Friendly" result))
+           (is (search "Concise" result)))
+      (ignore-errors (delete-file path)))))
+
+(test test-load-identity-file-missing-nil
+  "Contract 1: nil when file does not exist."
+  (let ((result (passepartout::load-identity-file
+                 "/tmp/memex-nonexistent-xxxx.org")))
+    (is (null result))))
+
+(test test-agent-identity-cached
+  "Contract 2+3: agent-identity returns cached value after load."
+  (let* ((path "/tmp/memex-test-identity2.org")
+         (content "### Preferences
+- Use shell cautiously"))
+    (with-open-file (f path :direction :output :if-exists :supersede)
+      (write-string content f))
+    (unwind-protect
+         (progn
+           (passepartout::load-identity-file path)
+           (let ((id (passepartout::agent-identity)))
+             (is (search "shell cautiously" id))))
+      (ignore-errors (delete-file path)))))
+
+(test test-agent-identity-empty-default
+  "Contract 2: returns empty string when nothing was loaded."
+  (let ((prev passepartout::*agent-identity*))
+    (unwind-protect
+         (progn
+           (setf passepartout::*agent-identity* nil)
+           (is (string= "" (passepartout::agent-identity))))
+      (setf passepartout::*agent-identity* prev))))