Align conftest mock herdr and unit test assertions with Claude's simplified session-based isolation and native herdr command updates

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

@@ -92,4 +92,5 @@ Job lifecycle execution events are persistently mirrored to an append-only log u
 - **Subscribe-Before-Publish**: The subscriber must be running before the agent starts publishing. The `submit` command handles this automatically by launching the subscriber in the background first.
 - **Fresh job_id Propagation**: Make sure the worker agent receives the correct `JOB_ID` generated for the current run, rather than reusing stale IDs from previous sessions.
 - **Brief delivery via file path**: For long or complex prompts, write the instructions to a file (e.g. `/tmp/task-brief.md`) and pass a short prompt pointing to the file path to prevent terminal buffer overflows.
+- **Prompts injected into a live agent session MUST be English, ASCII-only, and short** — this is exactly what `--prompt`/the `instructions` string sent to `run_agent()` end up as. Any Korean (or other non-ASCII) content the task needs to convey must go in a markdown brief file (e.g. `.mam/jobs/<id>/brief.md`, written in Korean is fine) that the injected prompt merely tells the agent to read. Two independent bugs in `send_keys_safe`'s paste-verification (in `lib.sh`) made this matter in practice: (a) its marker was taken with a byte-based `tail -c 24`, which can slice a multi-byte UTF-8 (e.g. Korean) character in half; (b) the rendered pane soft-wraps long lines at the terminal width, which can split the marker across two visual lines. Both are now fixed at the source (character-safe truncation + newline-stripped matching before comparison), but keeping injected prompts short/English/file-referencing is still the cheapest way to avoid ever exercising this edge case at all — it's also simply what `submit`'s own default instruction template already does (see `Core Commands` above).
 - **Batch Grouping**: Group non-overlapping tasks into batches to parallelize execution across multiple agent sessions, reducing overhead.

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

@@ -23,6 +23,13 @@ elif [[ -f "$SCRIPT_DIR/../../.env" ]]; then
   set -a; source "$SCRIPT_DIR/../../.env"; set +a
 fi
 
+# Source EARLY (before any herdr usage in run_agent) — this is what turns
+# plain `herdr` into the tmux-compat shim (herdr() function) and provides
+# resolve_herdr_workspace/send_keys_safe. Sourcing it late meant the
+# has-session pre-flight check below used to hit the real herdr binary with
+# a nonexistent subcommand and always fail.
+source "$SCRIPT_DIR/../lib.sh"
+
 # Pick an interpreter: prefer a project .venv, else python3.
 pick_python() {
   local py_bin
@@ -429,19 +436,19 @@ run_agent() {
     return 1
   fi
 
-  local _herdr="herdr"
-  if [ -n "${HERDR_SERVER_NAME:-}" ]; then
-    _herdr="herdr -L $HERDR_SERVER_NAME"
-  fi
+  # Auto-resolve isolation the same way resume/stop/create do — don't rely on
+  # the caller having exported HERDR_SERVER_NAME by hand. This is what lets
+  # delegation reach an agent living in an isolated herdr session (e.g. one
+  # created with --herdr-server) instead of silently looking in "default".
+  export HERDR_SERVER_NAME="$(resolve_herdr_workspace "$sess")"
 
-  if ! $_herdr has-session -t "$sess" 2>/dev/null; then
+  if ! herdr has-session -t "$sess" 2>/dev/null; then
     echo "ERROR: 에이전트 세션 '$sess'이 존재하지 않습니다. 작업을 위임하기 전에 먼저 에이전트 세션을 기동해 주세요." >&2
     echo "       팁: 'multi-agent-mux-resume' 또는 'multi-agent-mux-create'를 통해 에이전트를 먼저 생성할 수 있습니다." >&2
     return 1
   fi
 
   # Check role suitability
-  source "$SCRIPT_DIR/../lib.sh"
   local sess_role job_role
   sess_role=$(SESS_NAME="$sess" MAM_STATE_JSON="$(load_state_json)" "$PY" -c "
 import os, json
@@ -499,7 +506,11 @@ else:
     return 1
   fi
   
-  echo "작업이 세션 '$sess'에 전송되었습니다. (연결하려면: $_herdr session attach $sess)"
+  # NOTE: `herdr session attach` operates on whole herdr *sessions* (server
+  # instances), not an individual agent by its MAM name — `agent attach` is
+  # the real command for that. HERDR_SERVER_NAME is inlined so the printed
+  # command is copy-pasteable in a fresh shell that hasn't sourced lib.sh.
+  echo "작업이 세션 '$sess'에 전송되었습니다. (연결하려면: HERDR_SERVER_NAME=$HERDR_SERVER_NAME herdr agent attach $sess — lib.sh를 source한 셸에서 실행)"
   trap - EXIT
 }