chore(stop,resume): drop what Issue #63 left unused (Issue #63)

- workspace_uuid.py: the unused sys import.
- stop_session.sh: the orphan CAPTURE_ID and the blank padding that kept
  later line numbers; the inventory pins follow the move instead.
- lib.sh: capture_conversation_id, which nothing calls any more.
- resume SKILL.md: the flow names the session-id decision (session_ids.py),
  not resolve_session_id.sh.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.agents/skills/lib_py/workspace_uuid.py

@@ -1,7 +1,7 @@
 # workspace_uuid.py — workspace UUID discovery logic
 # Extracted from lib.sh find_workspace_uuid PYEOF block
 
-import os, sys, json
+import os, json
 from lib_py.verify_session import verify_session_uuid, mam_orchestrator_uuids, mam_row_own_uuid
 
 OWN_KEY = {