docs: add literate prose to naming-drift aliases and HITL gateway changes

Adds prose sections before every code block to satisfy the
prose-before-code discipline. Each backward-compatibility alias
(process-signal, perceive-gate, reason-gate, act-gate, inject-stimulus)
now has its own subsection explaining why it exists and what new code
should use instead.

Also:
- Fixes double #+end_src in core-loop-perceive.org
- Renames inject-stimulus → stimulus-inject in heartbeat-start and
  client-handle-connection (both already had aliases)
- Adds HITL interception prose to gateway-manager.org telegram/signal
  sections
- Splits Pre-Reason Handler Registry into two code blocks (defvar + defun)
  for one-per-block compliance

org/core-communication.org

@@ -38,7 +38,7 @@ The 6-character hex length supports messages up to ~16MB (0xFFFFFF bytes). This
 
 ** Actuator Registry
 
-The global registry mapping target keywords (~:cli~, ~:telegram~, ~:signal~, etc.) to their physical actuator functions. Extensible at runtime — skills can register new actuators via ~actuator-register~.
+The global registry mapping target keywords (~:cli~, ~:telegram~, ~:signal~, etc.) to their physical actuator functions. Extensible at runtime — skills can register new actuators via ~register-actuator~.
 
 #+begin_src lisp
 (defvar *actuator-registry* (make-hash-table :test 'equalp)
@@ -115,7 +115,7 @@ Reads a complete framed message from a TCP stream. Handles leading whitespace be
 
 The TCP server that accepts connections from CLI and TUI clients. Each connection gets a dedicated thread (~client-handle-connection~).
 
-The daemon sends a handshake message on connection, then enters a read loop, injecting each received message into the metabolic loop via ~inject-stimulus~. The ~:health-check~ message type is handled inline (not sent to the cognitive loop) so that health checks work even when the agent is busy.
+The daemon sends a handshake message on connection, then enters a read loop, injecting each received message into the metabolic loop via ~stimulus-inject~. The ~:health-check~ message type is handled inline (not sent to the cognitive loop) so that health checks work even when the agent is busy.
 
 #+begin_src lisp
 (defvar *daemon-socket* nil)
@@ -142,7 +142,7 @@ The daemon sends a handshake message on connection, then enters a read loop, inj
                                                      nil))))
                    (format stream "~a" (frame-message health-msg))
                    (finish-output stream)))
-                (t (inject-stimulus msg :stream stream))))))
+                (t (stimulus-inject msg :stream stream))))))
       (error (c) (log-message "CLIENT ERROR: ~a" c)))
     (ignore-errors (usocket:socket-close socket))))