feat(scope): implement workspace-scoped session isolation (A-1) and native Herdr session naming (A-5)

.agents/skills/lib.sh

@@ -48,7 +48,7 @@ LOCAL_BIN="${LOCAL_BIN:-$HOME/.local/bin}"
 _HERDR_SHIM_DIR_PATTERN="${_HERDR_SHIM_DIR_PATTERN:-/multi-agent-herdr-shim/}"
 _HERDR_SKILLS_BIN_PATTERN="${_HERDR_SKILLS_BIN_PATTERN:-/.agents/skills/.bin}"
 
-HERDR_SERVER_NAME="${HERDR_SERVER_NAME:-default}"
+HERDR_SESSION_NAME="${HERDR_SESSION_NAME:-default}"
 
 _resolve_real_herdr_path() {
   _REAL_HERDR_PATH="herdr"
@@ -90,23 +90,17 @@ _resolve_real_herdr() {
 }
 REAL_HERDR=$(_resolve_real_herdr)
 
-# Support parsing -L <server> before the subcommand
+# Support parsing -L <session> before the subcommand
 while [ "${1:-}" = "-L" ]; do
   if [ $# -lt 2 ]; then
     echo "herdr shim: -L requires an argument" >&2
     exit 1
   fi
-  export HERDR_SERVER_NAME="$2"
+  export HERDR_SESSION_NAME="$2"
   shift 2
 done
 
-# Herdr's real isolation boundary is `--session <name>` (a whole separate
-# server + socket, like tmux `-L`) — NOT `workspace create --label`, which is
-# just a named subdivision inside ONE server and provides no actual isolation
-# (agent/pane commands are server-global regardless of workspace). When
-# HERDR_SERVER_NAME names a non-default session, make sure its headless server
-# is actually running, then scope every real herdr call to it via `--session`.
-_MAM_SESSION="${HERDR_SERVER_NAME:-default}"
+_MAM_SESSION="${HERDR_SESSION_NAME:-default}"
 if [ "$_MAM_SESSION" = "default" ]; then
   _MAM_SESSION=""
 else
@@ -558,7 +552,7 @@ PYEOF
 # a workspace id. Real isolation is `--session <name>` (see `_MAM_SESSION` in the
 # generated wrapper) — a workspace label match provides no actual isolation
 # since agent/pane commands are server-global regardless of workspace.
-resolve_herdr_workspace() {
+resolve_herdr_session() {
   local session_name="$1"
   MAM_STATE_JSON="$(load_state_json)" SESSION_NAME="$session_name" python3 -c "
 import sys, os, json
@@ -566,16 +560,20 @@ name = os.environ['SESSION_NAME']
 d = json.loads(os.environ.get('MAM_STATE_JSON', '{}'))
 for s in d.get('herdr_sessions', []):
     if s.get('name') == name:
-        print(s.get('herdr_workspace') or s.get('herdr_server') or 'default')
+        print(s.get('herdr_session') or 'default')
         sys.exit(0)
-fallback = os.environ.get('HERDR_SERVER_NAME', '')
+fallback = os.environ.get('HERDR_SESSION_NAME', '')
 if not fallback or fallback == 'default':
     pwd = os.path.abspath(os.getcwd())
-    fallback = os.path.basename(pwd)
+    fallback = 'mam-' + os.path.basename(pwd).lower().replace('_', '-')
 print(fallback or 'default')
 "
 }
 
+resolve_herdr_workspace() {
+  resolve_herdr_session "$@"
+}
+
 # ---------------------------------------------------------------------------
 # derive_session_name <workspace> <agent>
 #