feat(sharedb): improve operation identity and history

[edocevol]

Summary

• add structured SubmitWithRequest with OpID/source+seq idempotency
• expose ShareDB-style operation history via GetOperations with BaseVersion, SubmittedOp, and committed Op metadata
• preserve compatibility for existing Submit callers while improving event/history identity metadata
• clone publisher event payloads to avoid subscriber mutation leaks

Test Plan

• go test ./...
• cd sharedb && go test ./...
• cd sharedb && go vet ./...
• cd sharedb && go test -race ./...