fix(b3): eliminate command -v herdr bash function false positive in preflight checks (100% PASS)

.agents/skills/lib.sh

@@ -50,9 +50,51 @@ _HERDR_SKILLS_BIN_PATTERN="${_HERDR_SKILLS_BIN_PATTERN:-/.agents/skills/.bin}"
 
 HERDR_SESSION_NAME="${HERDR_SESSION_NAME:-default}"
 
+_canonical_file() {
+  local p="$1" t d b i=0
+  while [ -L "$p" ] && [ "$i" -lt 40 ]; do
+    t="$(readlink "$p" 2>/dev/null)" || break
+    case "$t" in
+      /*) p="$t" ;;
+      *)  p="$(dirname "$p")/$t" ;;
+    esac
+    i=$((i + 1))
+  done
+  d="$(cd -P "$(dirname "$p")" 2>/dev/null && pwd -P)" || return 1
+  b="$(basename "$p")"
+  printf '%s/%s\n' "$d" "$b"
+}
+
+_is_shim_path() {
+  case "/$1/" in
+    *"/.mam/shim/"*|*-shim/*|*"$_HERDR_SHIM_DIR_PATTERN"*|*"$_HERDR_SKILLS_BIN_PATTERN"/*)
+      return 0 ;;
+  esac
+  return 1
+}
+
 _resolve_real_herdr_path() {
-  _REAL_HERDR_PATH="herdr"
+  local dir cand save_ifs="$IFS" real_path=""
+  IFS=:
+  for dir in $PATH; do
+    [ -n "$dir" ] || continue
+    _is_shim_path "$dir" && continue
+    [ -x "$dir/herdr" ] || continue
+    cand="$(_canonical_file "$dir/herdr" 2>/dev/null)" || cand="$dir/herdr"
+    [ -n "$cand" ] || cand="$dir/herdr"
+    _is_shim_path "$cand" && continue
+    real_path="$dir/herdr"
+    break
+  done
+  IFS="$save_ifs"
+  [ -n "$real_path" ] || return 1
+  _REAL_HERDR_PATH="$real_path"
   export _REAL_HERDR_PATH
+  printf '%s\n' "$real_path"
+}
+
+has_real_herdr() {
+  _resolve_real_herdr_path >/dev/null 2>&1
 }
 
 _init_herdr_isolation() {

.agents/skills/multi-agent-mux-create/SKILL.md

@@ -34,7 +34,10 @@ Before doing anything, verify the environment:
 
 ```bash
 # 1) herdr available and isolated server status
-command -v herdr || { echo "ERROR: herdr not installed"; exit 1; }
+# Use lib.sh's has_real_herdr, NOT `command -v herdr` / `type -P herdr`: once
+# lib.sh is sourced the former matches its herdr() function and the latter
+# matches the .mam/shim wrapper, so both pass on a host with no herdr (B-3).
+has_real_herdr || { echo "ERROR: herdr not installed"; exit 1; }
 echo "Herdr session name: ${HERDR_SESSION_NAME:-default}"
 
 # 2) claude / agy available

.agents/skills/multi-agent-mux-create/scripts/create_session.sh

@@ -81,7 +81,9 @@ fi
 [ -n "$AGENT" ]    || { echo "ERROR: --agent required" >&2; usage; exit 2; }
 [ -n "$ROLE" ]     || { echo "ERROR: --role required" >&2; usage; exit 2; }
 [ -d "$WORKSPACE" ] || { echo "ERROR: workspace $WORKSPACE not a directory" >&2; exit 1; }
-command -v herdr >/dev/null || type -P herdr >/dev/null || { echo "ERROR: herdr not installed" >&2; exit 1; }
+# B-3: `command -v herdr` matches lib.sh's herdr() function and `type -P herdr`
+# matches the .mam/shim wrapper, so both pass with no herdr installed.
+has_real_herdr || { echo "ERROR: herdr not installed" >&2; exit 1; }
 command -v "$AGENT" >/dev/null || { echo "ERROR: $AGENT CLI not in PATH" >&2; exit 1; }
 
 # Auth Check (OAuth check for agy, loggedIn check for claude, status for hermes)

.agents/skills/multi-agent-mux-delegate-job/multi-agent-mux-delegate-job

@@ -445,7 +445,8 @@ run_agent() {
     return
   fi
 
-  if ! command -v herdr >/dev/null 2>&1; then
+  # B-3: must probe for the real binary, not the herdr() function / shim wrapper.
+  if ! has_real_herdr; then
     echo "ERROR: this skill requires herdr (interactive agent sessions)." >&2
     echo "       Ensure herdr is installed and executable." >&2
     return 1

.agents/skills/multi-agent-mux-status/SKILL.md

@@ -28,11 +28,15 @@ This is the "what's running right now?" answer — faster than dispatching `mult
 ## Pre-flight
 
 ```bash
-command -v herdr
+has_real_herdr || { echo "ERROR: herdr not installed"; exit 1; }   # lib.sh helper (B-3)
 command -v python3
 test -f .mam/agent-sessions.yaml
 ```
 
+> `command -v herdr` and `type -P herdr` both report success even when herdr is
+> not installed — they match lib.sh's `herdr()` function and the `.mam/shim`
+> wrapper respectively. Always use `has_real_herdr`.
+
 If `agent-sessions.yaml` doesn't exist or is malformed → print clear error, exit 1. **Do not create it.** (Use `multi-agent-mux-create` first.)
 
 ## Workflow