chore: sync the frontend template from 4dc033c to 8157ad4

The product was materialized from the template at `4dc033c` and has stayed
on it through 43 template commits, so it was missing all three rounds of
adapter remediation — including files it never had, such as the shared
`abortable-operation` primitive and the `exact-snapshot` decoder that
later fixes are written against. Taking only the newest round was not
possible for that reason: the delta is coherent only as a whole.

The product had not touched `src/adapters` at all since materialization,
so the 140-file delta applied with a three-way merge and no conflicts.
`package.json` was the single overlap and merged cleanly: the product owns
`name`, the template contributed `check:adapter-inventory`,
`check:remediation-ledger` and the image-resolve-signal type fixture.
All 24 product-owned files — README, index.html, CI workflow, i18n
catalog, home page, generated schemas, evidence scripts, component and
visual snapshots — are byte-identical to `main`.

`template.lock.json` now pins the synced revision and tree.

Verified in this repository, not inherited from the template: six type
projects, lint, nine gates (adapter inventory, remediation ledger,
registries, diagnostics, realtime boundaries, architecture, browser
file/storage boundaries, optional recipes, documentation), the production
build, and 2,054 of 2,073 tests. The 19 failures are all in
`tests/unit/ci-artifact-contract.test.ts` and are the same pre-existing
sandbox RLIMIT, EMFILE, umask and `/tmp` permission behaviour the template
records; four suites that failed once under parallel load pass in
isolation.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/adapters/http/http-effect-certainty.ts

@@ -48,6 +48,30 @@ export function certaintyForAbandonedAttempt(
   }
 }
 
+/**
+ * §8.7. The conservative certainty lattice for one logical execution.
+ *
+ * `PhysicalAttemptState` describes only the attempt in flight. A new retry that
+ * has not been sent yet must never lower what an earlier attempt already
+ * established, so the executor joins observations into a monotonic accumulator.
+ */
+const CERTAINTY_RANK: Readonly<Record<MutationEffectCertainty, number>> =
+  Object.freeze({
+    NOT_STARTED: 0,
+    NOT_APPLIED: 1,
+    MAYBE_APPLIED: 2,
+    APPLIED_CONFIRMED: 3,
+  });
+
+export function joinMutationEffectCertainty(
+  current: MutationEffectCertainty,
+  observed: MutationEffectCertainty,
+): MutationEffectCertainty {
+  return CERTAINTY_RANK[observed] > CERTAINTY_RANK[current]
+    ? observed
+    : current;
+}
+
 export type ProblemEffectInput<Problem> = Readonly<{
   status: number;
   problem: Problem;