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fix(signals): a derived store's readers settle with its derive, not by a re-run (#4493)

* fix(signals): a derived store's derive re-runs when a source it pends on settles

`createStore(fn)` over an async memo. The derive went pending on the memo's
flight by propagation (`familyStatus` -> `wakeFamily`), and the store's
readers were parked on the derive itself. When the flight then settled
without the derive re-running (a rejection staged in its transaction, or a
re-ask that returned to the committed question), the settle walk retired
the memo from the derive but never reached the readers parked on it:
`isPending` stayed true forever (F-9), and the staged rejection's
transaction never landed, so the error never showed (F-12, D-41). The wake
now marks the derive blocked, as a pass that threw is, so the settle
re-runs it and its commit settles the family.

Found by the async-gen rerun on rc.20 (pair E3, rows #1 and #9).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

* chore(size): record the derived-store settle fix's sizes over next @ 7135a77a

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015hPxMkC3jg3Uivh65gvaf2

* fix(signals): a derived store's readers settle with its derive, not by a re-run

The derive pending by propagation (familyStatus -> wakeFamily) was marked
blocked so its source's settle re-ran it. For an async derive that re-run
is a new flight: when the source's rejection was staged, the walk in
stageError re-ran the derive in the same flush, ahead of the commit that
publishes the error to it. The new flight woke the family again, so a
reader beside isPending showed a second pending frame before the error
(#4463's error-once test, D-41).

The settle walk now settles the family instead (familyStatus with no
status -> settleFamily) when it retires a derive's pending without a pass
to re-run, as a memo's ... (continued)

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