fix: preserve committed CRDT updates when mutations throw

[hwisu]

YKS can commit changes and emit updates before a mutation callback or observer throws. Previously, the adapter dropped those collected updates when propagating the exception, leaving the live document ahead of peers and append-only persistence.

Carry committed deltas in CrdtMutationException and deliver them through the server's existing broadcast/change/store path before rethrowing the original cause. This covers client updates, Redis updates, local transactions, and document merges. Initial-load failures still discard the unpublished document; failures without committed updates retain their original exception. Public method signatures remain unchanged, with the additive exception documented in the API and README.

Validation

• Reproduced the bug on the base revision: the document retained its edit, but the regression test timed out waiting for onChange.
• Added 11 regression tests covering observer/callback failures, peer replay, append-log persistence, roots/origins, cancellation identity, Redis/skip-store policies, merge short-circuiting, failed loads, capture reuse, standard validation rollback, and delete-only commits.
• check consumerSmokeTest consumerKotlinCompatibilityTest passed against CI-pinned YKS 47095ae9 (0.2.15): 157 tests, zero failures or skips, including disposable Redis 8.2.5 and S3Mock integration tests, ABI checks, and Kotlin 2.3.21 consumer compatibility.
• The 18-test focused adapter/integration suite also passed against downstream-pinned YKS fcfa849a (0.2.14).
• Based on latest main at 0aad64332124f3e610430bbe7039b864653718d3.

Downstream compatibility review

Reviewed Norric API main/develop collaboration paths and the browser collaboration/answer-document paths. No production caller depending on discarded committed deltas was found. Client-origin append, Redis no-store, cancellation/reconnect handling, failed-load cleanup, and the absence of a success acknowledgement after failure are preserved. Standalone scratch YDoc workflows remain unchanged.

This is a source audit plus library integration tests, not a live Norric PostgreSQL/browser end-to-end run. Norric's dependency pins are unchanged; adopting the fix requires a later library release and dependency update. Direct CrdtDocument consumers now receive the documented exception envelope when a failed mutation has committed updates; server-facing callers still receive the original cause.