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>

docs/architecture/realtime-events-web-push-and-bounded-polling.md

@@ -34,6 +34,16 @@ capability가 설치됐거나 production-ready라는 뜻이 아니다.
 [Frontend ports, adapters, and boundaries](./frontend-ports-adapters-and-boundaries.md)
 를 따른다.
 
+
+## Bounded task lease와 DRAINING (R-02, R-03)
+
+non-cooperative effect/recovery authority 하나가 stream tail 전체를 영구
+wedge하지 못하도록, common coordinator는 각 task를 deadline으로 감싼다. deadline
+초과 시 commit capability는 즉시 취소되지만 task 자체는 `retainedTasks`에 남아
+stream을 `DRAINING`으로 유지한다. `close()`는 이 retain 집합이 실제로 settle해야
+성공을 반환한다. handoff coordinator도 같은 원칙으로 fail-close된 writer를
+`retiredWriters`에 보존한다.
+
 ## 0. 현재 상태와 목표 delta
 
 이 문서에서 설계 승인, reference source 존재, production 조합과 target browser의