feat(tree): implement isAuditableFromOutcome

[jason-ha]

AB#56693

isAuditableFromOutcome - Returns false when the change has more than one inner change, contains a schema change, or contains a data change with violated constraints.

Co-Authored-By: Claude Sonnet 4.6 noreply@anthropic.com

[github-actions]

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[Copilot]

Pull request overview

Adds a small SharedTree utility to decide whether a SharedTreeChange can be audited purely from post-apply outcome (HitL scenario), and introduces targeted unit tests for the new behavior. Also tightens ModularChangeset’s relationship to HasFieldChanges to align with readonly usage.

Changes:

• Added isAuditableFromOutcome(change) helper to reject non-auditable change shapes (multiple inner changes, any schema change, or violated constraints).
• Added a new spec file covering empty, single-data, multi-inner, schema, and constraint-violation cases.
• Updated ModularChangeset to extend Readonly<HasFieldChanges> to resolve readonly compatibility around fieldChanges.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
packages/dds/tree/src/test/shared-tree/isAuditableFromOutcome.spec.ts	Adds unit tests validating auditable vs non-auditable SharedTreeChange outcomes.
packages/dds/tree/src/shared-tree/isAuditableFromOutcome.ts	Introduces the new auditability predicate implementation.
packages/dds/tree/src/feature-libraries/modular-schema/modularChangeTypes.ts	Adjusts ModularChangeset inheritance to be readonly-compatible with HasFieldChanges.