WOR-67: migrate violation evidence to defect semantics

[Ldsystem]

Summary

• replace live violation-* evidence/evaluation vocabulary with defect-*
• add explicit, staged, marker-backed defect-migrate-store
• keep retired violation-* commands fail-only with migration/replacement guidance
• preserve evidence record IDs, schema, bytes, and generic On Violation rule prose

Migration safety

• normal defect commands fail before initialization when legacy, staging, or marker state exists
• migration validates legacy records, rebuilds the staged index, fingerprints both authorities, and atomically publishes
• only a valid matching marker permits migration-only crash recovery; unmarked or mismatched two-root states fail closed

Validation

• 29 focused evidence and migration tests pass
• 254 affected contract tests passed before the review-bounded test split; the same 29 focused cases pass after the split
• full CI-equivalent repository suite passed: 650 tests
• skill package, explicit-root rule validation, retired-vocabulary boundary, and git diff --check pass
• a copy of the real 77-record legacy store migrated with an identical aggregate record digest; the real store remains untouched until merge

Scope

• WorkBundle toolkit only; no execution-flow changes
• Linear: WOR-67
• Specification: https://linear.app/workbundle/document/specification-defect-evidence-and-evaluation-cutover-a3ec30fcbbc0
• Slack discussion: https://workbundleworkspace.slack.com/archives/C0BSA4ASR32/p1788087070915629

Breaking change: live command/store/rule vocabulary changes from violation to defect; operators run defect-migrate-store explicitly after upgrading.