borgmcp-shared 2.0.0

This release removes unused advisory claims from activity-log reads and advances
the coordination protocol to tag 14.

Compatibility

• The protocol tag changes from 13 to 14. Mixed tag 13 and tag 14 peers fail
  closed during credential-free preflight and must update together.
• The read-log response no longer carries a claims field. Claim visibility
  remains available through acknowledgement status, roster, and diagnostics.

Breaking API changes

• ReadLogResult and ReadLogResponse no longer expose claims.
• The unused ClaimRecord and ReadLogClaim exports are removed.
• The read-log decoder rejects the retired field instead of accepting both wire
  shapes.

Conformance

• The read-log-only durable-claim fixture is removed. Existing acknowledgement
  status and entry-query fixtures continue to verify that claims remain durable,
  distinct from acknowledgements, and unchanged by read-only operations.