fix(plugin): a subagent hand-back is not an operator prompt (#4785)

`<agent-message …>` turns were scored by auto-inject and the prompt rule
arm as if the operator had typed them, spending a retrieval and writing a
retrieval_logs row that reads as a real message (log 54355, found by the
#4772 review). Same class as #4142. Matched up to the tag name, since the
tag carries attributes; `<agent-messages>` and the tag named mid-sentence
are still retrieved against.

Plugin 2026.10.04.0125.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

plugin/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "scribe",
   "description": "Scribe for Claude Code: connects the scribe MCP server, adds the hooks that deliver live project state and relevant records at the right moment, ships the shared client-neutral Scribe skills (using-scribe, writing-plans, reporting-back, systematic-debugging, verification, brainstorming, reusing-code, shape-accounting), and syncs your saved Scribe Processes as skills (/scribe:sync).",
-  "version": "2026.10.03.1934",
+  "version": "2026.10.04.0125",
   "author": {
     "name": "Bryan Van Deusen"
   },

plugin/hooks/scribe_defs.sh

@@ -79,6 +79,7 @@ scribe_skip_prompt() {
   _scribe_prompt=${1#"${1%%[![:space:]]*}"}
   case "$_scribe_prompt" in
     "<task-notification>"*|\
+    "<agent-message>"*|"<agent-message "*|\
     "<command-name>"*|"<command-message>"*|"<command-args>"*|\
     "<local-command-stdout>"*|"<local-command-stderr>"*|"<local-command-caveat>"*)
       return 0 ;;