Docs: remove simulator-first runtime docs

[smithaldon1]

Summary

• Replaces simulator-first runtime docs and prompt guidance with the Docker/Demo-Factory external-source runtime direction.
• Rewrites simulator-specific demo docs and service READMEs to describe read-only connectors, FactoryEvent ingestion, Process Sentinel, API, and Workbench flow.
• Replaces old simulator-wording doc regression tests with a runtime-direction regression test and updates related Workbench/OPC-UA assertions.

Closes #233

Test evidence

• .venv/bin/python -m pytest services/simulator/tests/test_runtime_docs_transition.py services/simulator/tests/test_opcua_demo_server.py - 8 passed
• npm test in apps/web - 18 passed
• make test - 252 passed
• make lint - passed
• make typecheck - passed
• make docs - passed; docs checker not configured yet
• npm run lint in apps/web - passed
• npm run typecheck in apps/web - passed
• npm run build in apps/web - passed
• docker compose -f infra/docker/docker-compose.yml config - passed
• git diff --check - passed
• Issue wording scan run: rg -n "simulator|simulator-backed|make demo-data|make simulate|opcua-simulator" README.md docs apps services packages Makefile pyproject.toml. Remaining hits are historical learning-log/ADR entries, legacy Makefile/code/test fixtures, and UI/runtime wording intentionally left for Task: Update API and Workbench runtime wording #240.

Docs impact

• Current runtime docs now point contributors at Docker Compose plus external Demo-Factory protocol sources.
• Historical learning-log entries were preserved and a new learning entry documents the direction shift.

Follow-up work

• Task: Add Docker Compose runtime documentation #234 through Task: Add Compose smoke test #241 continue the Dockerized runtime implementation, API/Workbench wording cleanup, and Compose smoke test coverage.
• Task: Update API and Workbench runtime wording #240 should remove remaining user-facing Workbench/API simulator wording that is outside this docs-and-prompts cleanup.

[smithaldon1]

Reviewed and approved for merge