- start_strategy filters running check by mode so starting LIVE
won't clash with an active PAPER run and vice versa
- stop_strategy and resume_strategy accept optional mode param
so each tab stops/resumes only its own run
- paper_broker_service scopes all run lookups to mode=PAPER
- paper_mtm scopes run lookup to mode=PAPER
- routers/strategy exposes ?mode= query param on /stop and /resume
- run_service get_active_run_id and get_running_run_id already
support mode filtering (added in previous session)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>