Prove continuity materialization across repository classes

[szmyty]

Depends on #48
Closes #45
Part of #42

Summary

• add publish-safe fixtures for research/publication, library/CLI, site/application, organization/meta, and private creative repositories
• add a reviewed, digest-bound migration of Antidote's pinned legacy checkpoint without losing useful state or authored agent instructions
• exercise new, existing, provisional, opt-out, unsupported, conflict, upgrade, parallel reconciliation, repeat/no-op apply, and exact rollback paths
• validate every positive fixture semantically with EgoLint and snapshot the reviewed plan, surface, state, report, and rollback contracts
• keep fixture execution local-only: exact caller-supplied source revisions, no credentials, no provider client, and no mutable GitHub-state dependency
• wire canonical CI to acquire exact immutable inputs and build the pinned EgoLint source before running the offline checker

Review order

This PR is intentionally stacked on #48. Review and merge #48 first; this diff then contains only the fixture proof for #45.

Validation

• python3 -m unittest discover --start-directory tests --pattern "test_*.py" --verbose — 116 passed
• npm test -- --runInBand — 18 passed
• repository-continuity fixture checker — all six lifecycles and artifact contracts passed
• repository-continuity profile validation — passed
• workflow YAML parse and git diff --check — passed

[devactivity-app]

Pull Request Summary by devActivity

Metrics

Achievements

• @szmyty
  Earned XP: 15⭐
  Check Your Progress