passepartout: v0.5.0 File Reorganization

Extract non-core fragments using self-repair criterion:
- core-context -> symbolic-awareness (224 lines, fboundp guards in think())
- heartbeat generation -> symbolic-events (renamed events-start-heartbeat)

Rename 23 files for clarity and new naming scheme:
- 6 core: core-package, core-transport, core-pipeline,
          core-perceive, core-reason, core-act
- 13 system: symbolic-*, neuro-*, embedding-*, channel-shell
- 4 gateway: channel-cli, channel-tui-*, channel-tui-state

Utility relocations:
- markdown-strip -> programming-markdown
- plist-keywords-normalize -> programming-lisp
- cognitive-tool-prompt -> programming-tools
- VAULT-MEMORY -> security-vault
- Merge *backend-registry* into *probabilistic-backends*

Split gateway-messaging into channel-telegram/channel-signal/
channel-discord/channel-slack (4 independent skills)

Delete dead system-model.lisp (16-line wrapper)

Document self-repair criterion in DESIGN_DECISIONS

Version bump: 0.4.3 -> 0.5.0

org/channel-signal.org

@@ -0,0 +1,57 @@
+#+TITLE: Channel Signal (channel-signal.org)
+#+AUTHOR: Agent
+#+FILETAGS: :channel:signal:
+#+PROPERTY: header-args:lisp :tangle ../lisp/channel-signal.lisp
+
+* Channel Signal
+
+Extracted from gateway-messaging in v0.5.0. Isolated platform — Signal-specific poll and send logic.
+
+* Implementation
+
+#+begin_src lisp
+(in-package :passepartout)
+(defun signal-get-account ()
+  (vault-get-secret :signal))
+
+(defun signal-poll ()
+  "Polls Signal for new messages and injects them into the harness."
+  (let ((account (signal-get-account)))
+    (when account
+      (handler-case
+          (let* ((output (uiop:run-program (list "signal-cli" "-u" account "receive" "--json")
+                                            :output :string :error-output :string :ignore-error-status t))
+                 (lines (cl-ppcre:split "\\\\n" output)))
+            (dolist (line lines)
+              (when (and line (> (length line) 0))
+                (let* ((json (ignore-errors (cl-json:decode-json-from-string line)))
+                       (envelope (cdr (assoc :envelope json)))
+                       (source (cdr (assoc :source envelope)))
+                       (data-message (cdr (assoc :data-message envelope)))
+                       (text (cdr (assoc :message data-message))))
+                  (when (and source text)
+                    (log-message "SIGNAL: Received message from ~a" source)
+                    (unless (ignore-errors (hitl-handle-message text :signal))
+                      (stimulus-inject
+                       (list :type :EVENT
+                             :meta (list :source :signal :chat-id source)
+                             :payload (list :sensor :user-input :text text)))))))))
+        (error (c) (log-message "SIGNAL POLL ERROR: ~a" c))))))
+
+(defun signal-send (action context)
+  "Sends a message via Signal."
+  (declare (ignore context))
+  (let* ((payload (getf action :payload))
+         (meta (getf action :meta))
+         (chat-id (or (getf meta :chat-id) (getf payload :chat-id) (getf action :chat-id)))
+         (text (or (getf payload :text) (getf action :text)))
+         (account (signal-get-account)))
+    (when (and account chat-id text)
+      (handler-case
+          (uiop:run-program (list "signal-cli" "-u" account "send" "-m" text chat-id)
+                            :output :string :error-output :string)
+        (error (c) (log-message "SIGNAL ERROR: ~a" c))))))
+#+end_src
+
+
+#+end_src