Contain field errors on the subprocessors and updates lists to an inline
fallback instead of the whole page, and make the retry actually recover.
Introduce ListErrorBoundary, which keeps refetch above the boundary and
resets only after the network refetch settles (a bare boundary reset
re-reads the same errored record and throws again). Wire the subprocessors
and updates lists to refetch network-only on retry, and mark the item
fragments @throwOnFieldError so a row error lands below the boundary.
Fix the home sections, whose reset-only retry could not clear a field
error from the preloaded query, to reload the page instead. Generalize the
retry guidance in the error-handling guide (reset vs refetch vs reload).
Signed-off-by: Émile Ré <emile@probo.com>