feat(release): align v1.2 architecture cohesion

[stacknil]

Summary

• align project identity around telemetry-lab==1.2.0, primary package telemetry_lab, and compatibility entrypoints for telemetry_window_demo
• add unified telemetry-lab run <demo> and telemetry-lab verify commands across all five demos
• add deterministic run_manifest.json artifacts plus schema coverage and schema compatibility docs
• add property tests for window boundaries and dedup cooldown behavior

Boundary

• v1.2 is an Architecture Cohesion Release, not demo expansion
• notebooks remain auxiliary exploration only; the core pipeline stays headless and synthetic-local
• no production SIEM, dashboard, alert routing, real-time ingestion, autonomous response, or final-verdict claim

Validation

• telemetry-lab verify passed
  • artifact regeneration: 29 committed artifacts matched, 6 visual snapshots regenerated without byte comparison
  • schema validation: 3 passed
  • full test suite: 186 passed
• git diff --cached --check passed before commit

Notes

• Existing local .pytest-artifacts-* directories still emit Windows permission warnings during git status; they are ignored local leftovers and are not part of this PR.