Normalize live query values

Parent

Live queries expose and cache their latest emitted value consistently, including undefined and null.

Normalize live undefined emissions to null in runtime data and published DataTags, selectors, and initial-data types.
Verify undefined-only, null-only, and value-then-undefined streams through ordinary factory tests against the workspace Query Core version.
Raise the minimum to a verified eligible fixed version at or above 5.103.1, or document and prove equivalent adapter compensation.
Preserve undefined elements in accumulated histories and unchanged mutation results; retain empty-live-stream failure.
Prove first-emission success while an open stream remains fetching and amend normalization/stream vocabulary and decisions.