refactor: update multi-agent rules to TMUX & refactor MAM skills scripts

- Update .agents/MULTI_AGENT_RULES.md & .ko.md to align with TMUX concepts
- Add .agents/INSTALL.md guide for MAM setup and workflows
- Clean up legacy markdown reports under .agents/reports/
- Refactor MAM scripts in .agents/skills/ (rename resolve_herdr_session to resolve_herdr_workspace)
- Improve workspace pane splitting/re-use logic in lib.sh
- Reduce paste safety sleep in send_keys_safe and support linking ~/.claude.json

.agents/skills/multi-agent-mux-status/scripts/status.sh

@@ -93,7 +93,7 @@ def get_job_status(s):
 sessions_detail = []
 for s in d.get('herdr_sessions', []):
     name = s.get('name', '?')
-    server = s.get('herdr_session') or s.get('herdr_workspace') or s.get('herdr_server') or 'default'
+    server = s.get('herdr_workspace') or s.get('herdr_server') or 'default'
     jid, jstatus = get_job_status(s)
     pane = s.get('pane') or {}
     sessions_detail.append({
@@ -197,7 +197,7 @@ if not sessions:
     print("(no sessions registered)")
 for s in sessions:
     name = s.get('name', '?')
-    server = s.get('herdr_session') or s.get('herdr_workspace') or s.get('herdr_server') or 'default'
+    server = s.get('herdr_workspace') or s.get('herdr_server') or 'default'
     status = s.get('status', '?')
     herdr = 'alive' if f"{name}|{server}" in alive else 'dead'
     cmd = (s.get('pane') or {}).get('cmd', '?')