* ci: run native Windows PR jobs in a separate workflow
GitHub re-runs failed jobs only after a whole run finishes, so slow Windows jobs blocked re-running failed Linux jobs. CI Windows now owns the native Windows jobs and the Windows x64 Python runtime target, with its own required 'windows checks passed' verdict.
Refs #6893
* ci: run Python PR jobs in a separate workflow
Python rarely fails while the Windows lanes run long, so the Python SDK suite and the Linux/Windows x64 runtime matrix move into CI Python. The three pull-request workflows can now be re-run without waiting for each other, and branch protection gains "python checks passed" beside the existing verdicts.
Refs #6893
* docs: record the three PR verdicts in the failover runbook
* test: pin the shared environment across the PR workflows
* test: read the python SDK lane from CI Python
* test(sdk): parse session JSONL frames in the keyless smoke
Node 24.19 returned only the first frame of a concatenated zstd log, so the single JSON.parse saw just the header; 24.22 returns every frame and the JSONL body broke the parse. Read frames explicitly and select the main session by its header so both versions agree.
The per-platform failover repository variables (DSH_CI_FAILOVER_LINUX and
DSH_CI_FAILOVER_WINDOWS) accept a third value alongside the existing
selfhosted routing. Set by a repository writer, the value retargets the
always-on pull-request and master lanes onto the matching hosted-runner
labels (16-core pools map to the 16-vCPU tier, standard legs to 4-vCPU);
unset or any other value keeps today's runners, so the leg is dormant until
a writer opts in - a canary path for capacity fallback, never the default.
Participating jobs: the three enterprise Linux workers, the node-compat
legs, the four Windows lanes, and the all-checks-passed verdict in ci.yml;
expected-filenames; the sandbox bwrap leg; and the two manual benchmark
matrices (4-32 vCPU tiers map to equivalents; 64/96-core rows keep the
fleet labels). Everything pinned to its own runner by spec, credential, or
host capability keeps it under every value, and the release-shaped chains
stay entirely hosted. request-review.yml was retired on master while this
work was in flight and the branch takes the deletion.
Specs pin the new branches: ci-workflow.spec.ts asserts the labels appear
in the extended selectors, and ci-compatible-selfhosted.spec.ts evaluates
the routing mode.
imccyu