Guard the agent runtime against admin-UI deactivation on managed installs

.github/workflows/shell.yml

@@ -131,6 +131,14 @@ jobs:
       - name: Run tests/kimaki-no-default-channel.sh
         run: ./tests/kimaki-no-default-channel.sh
 
+  runtime-guard:
+    name: runtime deactivation guard (#328)
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Run tests/runtime-guard.sh
+        run: ./tests/runtime-guard.sh
+
   posture:
     name: installed-source posture (#314)
     runs-on: ubuntu-latest

lib/runtime-guard.sh

@@ -0,0 +1,130 @@
+#!/bin/bash
+# lib/runtime-guard.sh — protect the agent runtime from admin-UI deactivation.
+#
+# On a managed install the site owner has wp-admin access and no reason to
+# understand the plugins list. Deactivating Data Machine there costs them their
+# assistant's memory and tools, with no obvious way back.
+#
+# This guards the ADMIN UI only. `wp plugin deactivate data-machine` stays
+# available because that is the operator's recovery path. The accident happens
+# in wp-admin; the recovery happens on the CLI. See #328.
+#
+# Deliberately NOT an mu-plugin move (#323): WordPress fatal-error recovery
+# pauses a plugin that fatals and cannot do that for an mu-plugin, so relocating
+# the runtime would turn a broken assistant into a white screen on a live site.
+#
+# Public surface:
+#   runtime_guard_mu_plugin_path
+#   runtime_guard_sync            # installs under managed, removes otherwise
+#
+# Honors DRY_RUN (logs intent, makes no changes).
+
+runtime_guard_mu_plugin_path() {
+  if [ -z "${SITE_PATH:-}" ]; then
+    return 1
+  fi
+  printf '%s' "$SITE_PATH/wp-content/mu-plugins/wp-coding-agents-runtime-guard.php"
+}
+
+# Plugin basenames to protect, one per line.
+#
+# `data-machine` is guarded unconditionally because wp-coding-agents installs it
+# on every agent install — it is a property of the product, not of one site.
+# Companions vary per install, so they are DISCOVERED from what is actually
+# active rather than assumed. Naming a stack this tool has not inspected is the
+# #320 mistake.
+runtime_guard_plugins() {
+  if [ "${DRY_RUN:-false}" = true ] || [ -z "${SITE_PATH:-}" ] || [ ! -f "$SITE_PATH/wp-config.php" ]; then
+    printf '%s\n' 'data-machine/data-machine.php'
+    return 0
+  fi
+
+  local discovered
+  discovered="$(wp_cmd eval 'foreach ( (array) get_option( "active_plugins", array() ) as $p ) { if ( 0 === strpos( $p, "data-machine" ) ) { echo $p, "\n"; } }' 2>/dev/null || true)"
+
+  if [ -z "$discovered" ]; then
+    printf '%s\n' 'data-machine/data-machine.php'
+    return 0
+  fi
+
+  printf '%s\n' "$discovered" | tr -d '\r' | sed '/^$/d' | sort -u
+}
+
+runtime_guard_sync() {
+  local file
+  file="$(runtime_guard_mu_plugin_path)" || {
+    warn "  runtime_guard_sync: SITE_PATH not set — skipping"
+    return 1
+  }
+
+  # Engineering installs have a developer at the keyboard; the guard would be
+  # noise. Remove any guard left behind by a posture switch.
+  if ! source_policy_is_managed; then
+    if [ -f "$file" ]; then
+      if [ "${DRY_RUN:-false}" = true ]; then
+        echo -e "${BLUE}[dry-run]${NC} Would remove runtime guard mu-plugin $file"
+        return 0
+      fi
+      rm -f "$file"
+      log "  Removed runtime guard mu-plugin (posture is ${POSTURE:-engineering}): $file"
+      if [ -n "${UPDATED_ITEMS+x}" ]; then
+        UPDATED_ITEMS+=("runtime guard removed")
+      fi
+    fi
+    return 0
+  fi
+
+  local template="$SCRIPT_DIR/templates/wp-coding-agents-runtime-guard.php"
+  if [ ! -f "$template" ]; then
+    warn "  runtime_guard_sync: missing template $template"
+    return 1
+  fi
+
+  local entries=""
+  local plugin
+  while IFS= read -r plugin; do
+    [ -n "$plugin" ] || continue
+    entries="${entries}		'$(printf '%s' "$plugin" | sed "s/'/\\\\'/g")',"$'\n'
+  done < <(runtime_guard_plugins)
+
+  if [ -z "$entries" ]; then
+    warn "  runtime_guard_sync: no runtime plugins resolved — not writing an empty guard"
+    return 1
+  fi
+
+  local rendered
+  rendered="$(RUNTIME_GUARD_ENTRIES="$entries" python3 - "$template" <<'PY'
+import os, pathlib, sys
+template = pathlib.Path(sys.argv[1]).read_text(encoding="utf-8")
+begin = "\t\t// BEGIN wp-coding-agents-guarded-plugins\n"
+end = "\t\t// END wp-coding-agents-guarded-plugins"
+start = template.index(begin) + len(begin)
+stop = template.index(end)
+sys.stdout.write(template[:start] + os.environ["RUNTIME_GUARD_ENTRIES"] + template[stop:])
+PY
+)" || {
+    warn "  runtime_guard_sync: could not render guard template"
+    return 1
+  }
+
+  if [ "${DRY_RUN:-false}" = true ]; then
+    echo -e "${BLUE}[dry-run]${NC} Would install runtime guard mu-plugin at $file guarding:"
+    printf '%s' "$entries" | sed 's/^/    /'
+    return 0
+  fi
+
+  local dir="${file%/*}"
+  mkdir -p "$dir"
+
+  if [ -f "$file" ] && printf '%s\n' "$rendered" | cmp -s - "$file"; then
+    service_file_normalize_perms "$file"
+    return 0
+  fi
+
+  printf '%s\n' "$rendered" > "$file"
+  service_file_normalize_perms "$file"
+  log "  Installed runtime guard mu-plugin: $file"
+  if [ -n "${UPDATED_ITEMS+x}" ]; then
+    UPDATED_ITEMS+=("runtime deactivation guard")
+  fi
+}

setup.sh

@@ -23,7 +23,7 @@ set -e
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 
 # Source shared modules
-for lib in common detect source-policy wordpress infrastructure data-machine carried-plugins homeboy ai-gateway skills summary cli-transport cli-channel runtime-signature agents-md-guidance; do
+for lib in common detect source-policy wordpress infrastructure data-machine carried-plugins homeboy ai-gateway skills summary cli-transport cli-channel runtime-signature runtime-guard agents-md-guidance; do
   source "$SCRIPT_DIR/lib/${lib}.sh"
 done
 
@@ -512,6 +512,7 @@ runtime_generate_instructions
 runtime_merge_mcp_servers
 install_skills
 cli_transport_install
+runtime_guard_sync
 install_chat_bridge
 datamachine_worker_install
 print_summary

templates/wp-coding-agents-runtime-guard.php

@@ -0,0 +1,124 @@
+<?php
+/**
+ * Plugin Name: wp-coding-agents — runtime deactivation guard
+ * Description: Prevents the agent runtime from being deactivated or deleted
+ *              through the wp-admin plugins screen on managed installs.
+ *              Managed by wp-coding-agents setup/upgrade — do not edit by hand.
+ *
+ * WHY THIS EXISTS
+ *
+ * On a managed install the site owner has wp-admin access and no reason to
+ * understand the plugins list. Deactivating Data Machine there costs them their
+ * assistant's memory and tools, with no obvious way back for a non-technical
+ * user.
+ *
+ * WHY NOT AN MU-PLUGIN MOVE
+ *
+ * Relocating the runtime into mu-plugins would also prevent deactivation, but
+ * WordPress fatal-error recovery PAUSES a plugin that fatals and cannot do that
+ * for an mu-plugin. Making the runtime unkillable would also make it
+ * unpausable, turning a broken assistant into a white screen on a live site.
+ * See Extra-Chill/wp-coding-agents#328 and #323.
+ *
+ * WP-CLI IS DELIBERATELY NOT GUARDED
+ *
+ * `wp plugin deactivate data-machine` stays available. That is the operator's
+ * recovery path and was used during the managed-posture rollout. This guard
+ * targets the admin UI, which is where the accident happens, not the CLI, which
+ * is where recovery happens.
+ *
+ * @package wp-coding-agents
+ */
+
+defined( 'ABSPATH' ) || exit;
+
+/**
+ * Plugin basenames this install protects.
+ *
+ * Written by wp-coding-agents at setup/upgrade time between the markers below.
+ *
+ * @return string[]
+ */
+function wp_coding_agents_guarded_runtime_plugins(): array {
+	$guarded = array(
+		// BEGIN wp-coding-agents-guarded-plugins
+		// END wp-coding-agents-guarded-plugins
+	);
+
+	/**
+	 * Filters the plugins protected from admin-UI deactivation.
+	 *
+	 * @param string[] $guarded Plugin basenames, e.g. 'data-machine/data-machine.php'.
+	 */
+	$filtered = apply_filters( 'wp_coding_agents_guarded_runtime_plugins', $guarded );
+
+	return is_array( $filtered ) ? array_values( array_filter( array_map( 'strval', $filtered ) ) ) : $guarded;
+}
+
+/**
+ * Replace the Deactivate and Delete links with a short explanation.
+ *
+ * The owner is told why rather than shown a row with missing controls, which
+ * reads as a broken page.
+ *
+ * @param string[] $actions     Action links keyed by action.
+ * @param string   $plugin_file Plugin basename.
+ * @return string[]
+ */
+function wp_coding_agents_guard_plugin_action_links( $actions, $plugin_file ) {
+	if ( ! is_array( $actions ) || ! in_array( (string) $plugin_file, wp_coding_agents_guarded_runtime_plugins(), true ) ) {
+		return $actions;
+	}
+
+	unset( $actions['deactivate'], $actions['delete'] );
+
+	$actions['wp-coding-agents-guard'] = '<span aria-label="' . esc_attr__( 'Required by this site\'s AI assistant', 'wp-coding-agents' ) . '">'
+		. esc_html__( 'Required by your assistant', 'wp-coding-agents' )
+		. '</span>';
+
+	return $actions;
+}
+add_filter( 'plugin_action_links', 'wp_coding_agents_guard_plugin_action_links', 100, 2 );
+add_filter( 'network_admin_plugin_action_links', 'wp_coding_agents_guard_plugin_action_links', 100, 2 );
+
+/**
+ * Reject a guarded deactivation or deletion request.
+ *
+ * Hiding the links is presentation only — the request can still be issued by
+ * URL, by a bulk action, or by any code calling deactivate_plugins(). This is
+ * the half that actually holds.
+ *
+ * Only wp-admin requests are refused. WP-CLI, WP-Cron, and REST are left alone
+ * so operator recovery and programmatic management keep working.
+ *
+ * @param string|string[] $plugins Plugin basename(s) being acted on.
+ * @return void
+ */
+function wp_coding_agents_block_guarded_deactivation( $plugins ): void {
+	if ( ( defined( 'WP_CLI' ) && WP_CLI ) || wp_doing_cron() ) {
+		return;
+	}
+
+	if ( ! function_exists( 'is_admin' ) || ! is_admin() ) {
+		return;
+	}
+
+	$guarded  = wp_coding_agents_guarded_runtime_plugins();
+	$requested = is_array( $plugins ) ? $plugins : array( $plugins );
+	$blocked   = array_intersect( array_map( 'strval', $requested ), $guarded );
+
+	if ( empty( $blocked ) ) {
+		return;
+	}
+
+	wp_die(
+		esc_html__(
+			'This plugin runs your site\'s AI assistant and cannot be deactivated or deleted from here. Ask your site operator if you need it changed.',
+			'wp-coding-agents'
+		),
+		esc_html__( 'Action not permitted', 'wp-coding-agents' ),
+		array( 'response' => 403, 'back_link' => true )
+	);
+}
+add_action( 'deactivate_plugin', 'wp_coding_agents_block_guarded_deactivation', 1 );
+add_action( 'delete_plugin', 'wp_coding_agents_block_guarded_deactivation', 1 );