* chore(release): 0.225.4

Carries #1230: a re-prompted scope owner may run its next attempt in a new
execution environment. Without it, a root that completed a turn and was
re-prompted burned every driver attempt on the same rejected materialization and
settled no-winner.

The Discovery Lab needs this published to run a multi-turn pi play; its last two
presses ended at exactly this wall (agent-runtime#1225).

* chore(release): regenerate version-stamped proposal fixtures for 0.225.4

The fixtures embed runtimeVersion, so tests/testing-fixture.test.ts fails on any
release commit until they are regenerated. Produced by the repo's own generator,
scripts/generate-agent-improvement-proposal-fixtures.ts; check:testing-fixture
now reports them current.

* chore(release): restamp the version-gated docs for 0.225.4

docs:check regenerates docs/api/primitive-catalog.md from package.json and then
runs the freshness gate, which also reads the hand-written version line in
docs/canonical-api.md. Both still read 0.225.3, so the release commit failed
the gate. Regenerated the catalog and restamped the prose line.