v0.4: Fix collision + ensure root tests run in CI

[LalaSkye]

v0.4 Correction Patch: Collision Fix + CI Expansion

Changes

1. fix: block reset() from RED -- aligns root stop_machine.py with canonical terminal invariant (RED is absorbing)
2. refactor: rename primitives/stop-machine -> stop-machine-v0 -- eliminates module name collision with repo name
3. refactor: rename primitives/authority-gate -> authority-gate-v0 -- consistent naming, avoids future collisions
4. fix: update demo imports -- examples/demo_stop_machine.py and demo_authority_gate.py point to renamed folders
5. ci: expand test runner -- python -m pytest . -v now covers root-level AND primitive tests (NON-NEGOTIABLE)

Canonical home

constraint-workshop remains the canonical source for all primitives.

Rollback

Single PR -- revert this one PR to undo all changes.