Release v4.125.0

Summary

Reactions that declare runs as system are now executable: the identity is admitted into the executable semantic model as ESM v10, and the reference evaluator runs the reaction's commands as that system identity.

Added

• ESM v10 (language and semantic 10.0, schemaVersion: 10) admits the reaction system identity as the SemanticReaction member runsAs ({"kind":"system","roles":[...]}, roles sorted). Only models that declare runs as select it; every other model keeps its version and bytes, and strict readers for schema 9 and earlier reject the member (#383)
• Specifications run a reaction's invoked and returned commands as an authenticated system identity holding exactly the declared roles, so a role-gated invocation succeeds with runs as and is refused without it. Claim conditions against this identity are unknown and deny, and a specification's given caller is never passed to invocations

Changed

• Binding no longer refuses runs as with PLAY0268, and MCP readiness no longer lists it as unsupported
• The TimeTracking sample grants its approved-week automation a dedicated PayrollAutomation role as the alternative to the Finance department claim, which human payroll callers still need