fix: release QA hardening across processing, media, security, and CI gates (#649)

A release-readiness QA pass over the whole product. The commits split into
defects a user would hit and gates that were reporting green while measuring
nothing.

## Fixes that change behaviour

Rate limiting was bypassable on every install: TRUST_PROXY defaulted to true, so
request.ip came from a client-set header and a forged X-Forwarded-For got past
the login limiter. The default is now a private-network trust list.

A transient Postgres outage stranded in-flight jobs, leaving finished output on
disk with no row pointing at it. A reconciler now resolves those rows and adopts
the bytes rather than dropping the work.

A Redis connection that moved to a new address wedged every read-blocked
consumer, so completions stopped signalling while health still answered 200.
Socket timeouts plus subscriber pings recover it.

Installing more than one AI bundle left the shared venv multi-versioned and
silently broke three tools. The installer now reconciles distributions to one
version each.

Converting an image to JXL at quality 1 through 4 returned a 500, because
libjxl 0.7 rejects the distance those values compute. The quality is floored at
what the encoder honours. A missing ffmpeg was also reported to the user as a
corrupt upload; it now says the engine is unavailable.

RAW uploads reached an unpatched LibRaw on arm64, so it is built from source at
0.22.2, and the release scan was split so it can fail on an unfixed critical
instead of hiding it behind ignore-unfixed.

## Gates that could not fail

Two mutation lanes ran zero mutants because Stryker crawled the gitignored docs
build; coverage discarded its whole report on any failing test; the lint gate
skipped root tests, scripts, and two workspaces; and several generated matrices
counted a host missing ffmpeg as a passing tool. Each now measures what it
claims.

Full evidence and the outstanding release items are tracked locally and are not
part of this branch.

apps/docs/ko/guide/architecture.md

@@ -1,8 +1,9 @@
 ---
 description: "SnapOtter의 모노레포 구조, 앱 및 패키지 아키텍처, 요청 라이프사이클, 리소스 사용량."
-i18n_output_hash: 90a5f3b46d1e
-i18n_source_hash: a53946e760b0
+i18n_source_hash: 50e076925c4b
 i18n_provenance: human
+i18n_output_hash: 45e8d01172a0
+i18n_hash_version: 2
 ---
 
 # 아키텍처 {#architecture}
@@ -52,7 +53,7 @@ Python 스크립트가 살고 있습니다 `packages/ai/python/`. 대규모 옵
 
 ### API (`apps/api`) {#api-apps-api}
 
-다섯 가지 모달리티(image, video, audio, PDF, file)에 걸친 241개의 도구 경로를 노출하는 Fastify v5 서버로, 다음을 처리합니다.
+다섯 가지 모달리티(image, video, audio, PDF, file)에 걸친 243개의 도구 경로를 노출하는 Fastify v5 서버로, 다음을 처리합니다.
 - 파일 업로드, 임시 워크스페이스 관리, 영구 파일 저장
 - 사용자 파일 라이브러리(`user_files` 테이블): 저장된 편집본은 기본적으로 독립적인 새 파일로 저장되며, 원본을 덮어쓸 때는 부모와 연결된 버전으로 저장됩니다. 어떤 도구가 적용되었는지(`toolChain`)를 기록하고 Files 페이지를 위한 썸네일이 자동 생성됩니다
 - 도구 실행(각 도구 요청을 이미지 엔진 또는 AI 브리지로 라우팅)