Copilot review round 2.
The contract claimed an unstable `read`/`whenAbsent` trips React's "The
result of getSnapshot should be cached" error. It does not. Measured on
React 19: an inline `read` closure throws nothing, logs nothing, and forces
no extra render pass. React's dev check calls getSnapshot twice within a
single render, where the closure is unchanged, so the cache answers both
calls identically and the warning never fires.
The real cost is quiet — a fresh value every render, defeating downstream
useMemo/React.memo/effect deps — which is a better reason to state the
contract than an error that never arrives.
Also stop requiring module scope for every fallback. A primitive
`whenAbsent` (`false`, `undefined`, `"disconnected"`) is stable under
Object.is and is passed inline throughout these hooks, so the rule
contradicted the code it was describing. Only object/array fallbacks need a
constant, which is what NO_TOOLS and NO_PAGINATION are.
Signed-off-by: cliffhall <cliff@futurescale.com>