chore: prepare the 2.2.0 release (#660)

Bumps every version surface to 2.2.0, fixes a latent version-coupling bug in the
OCR runtime tests, and stops an absent GPU runner from silently stalling a
release.

Version surfaces: scripts/sync-version.sh covers the 11 workspaces, APP_VERSION,
and the docs release commands across all locales. Root package.json plus the
three surfaces the script never reaches are done by hand: the DOCKERHUB.md banner
and tag table, the docker-tags.md pinning table in 21 locales, and the example
runtimeVersion in tools/image/ocr.md in 21 locales. The release-notes archive step
is deliberately not pre-run, so the notes text stays editable until the release.

Latent bug: runtime-state rejects any runtime whose compatibility.snapotterVersion
is not exactly APP_VERSION, and five fixtures pinned the literal 2.1.0. Since
semantic-release rewrites APP_VERSION on every release, the first PR after any
bump would have gone red for a reason nobody would trace to the release. The
fixtures now derive from APP_VERSION.

GPU runner: sign-ocr-index needs verify-ocr-nvidia on self-hosted hardware, and
the gated manifest job needs ai-bundles, so a missing runner queued instead of
failing and produced no image tags. preflight-gpu-runner claims the same labels
with no dependencies, so it is scheduled first and validates the GPU before the
90-minute build. An API preflight is impossible because listing self-hosted
runners needs Administration:read, which GITHUB_TOKEN cannot hold, so RELEASE.md
carries the maintainer-side check.

apps/docs/ja/tools/image/ocr.md

@@ -76,7 +76,7 @@ curl -X POST http://localhost:1349/api/v1/tools/image/ocr \
     "provider": "CPUExecutionProvider",
     "degraded": false,
     "warnings": [],
-    "runtimeVersion": "2.1.0",
+    "runtimeVersion": "2.2.0",
     "modelVersion": "PP-OCRv6-best-v1-medium"
   }
 }