JVNAUTOSCI-1378 Clarify thinking card workflow progress

[witbrock]

Summary

• expose a canonical live workflow_stage_path and explicit workflow-discovery outcome in /von/progress
• emit workflow-dispatch selection details from the orchestrator so the Thinking card can show which workflow was chosen
• render canonical workflow stages and explicit no-match states in the Thinking card, with targeted tests and a manual update

Validation

• pdm run pytest tests/backend/test_tool_progress_liveness.py -q
• npx jest src/frontend/web/von_interface/static/js/test/chatTab.test.js --runInBand --silent
• npx pyright src/backend/server/routes/von_routes.py src/backend/integrations/internal_mcp/orchestrator.py tests/backend/test_tool_progress_liveness.py