Three fetch initiators (search debounce, paging, push/coalesce reload) could
each have a LoadDataAsync flight in flight at once; completion order was not
call order, so a slow, stale flight could resolve after a newer one and
clobber the grid the operator was already looking at. Add a monotonic
_requestGeneration counter, bumped at fetch start and checked at apply —
last-write-wins by generation, not by whichever await resolves first.
Separately, the filter-debounce timer wrote `_currentPage = 1` directly on
its raw System.Threading.Timer callback thread — a Blazor threading
violation, since component state may only be mutated on the renderer's
sync context — and that write was not covered by the generation guard at
all. LoadDataAsync now takes a resetToFirstPage flag, resolves the target
page into a local, and applies it only behind the same generation check as
every other piece of state, via a new DispatchFilterReloadAsync that
marshals through InvokeAsync like the existing push-reload path.
Tests (DeploymentsRequestGenerationTests, bUnit): a delayed stale flight
arriving after a newer one does not overwrite the grid; a stale
filter-debounce flight does not reset the page after a newer navigation.
Both driven deterministically via TaskCompletionSource-backed repository
stubs. Verified to fail against the unfixed code (swapped via
`git show HEAD:<path>`, not `git stash` — repo-wide and unsafe across the
parallel worktree wave).
Joseph Doherty
21d50d4406