* ci: trial smaller Blacksmith static and observational runners
* ci: measure the 16-vCPU control for runner sizing
* ci: use 4-vCPU static and 8-vCPU observational runners
* ci: retain 8-vCPU static runner for completion time
* ci: right-size Blacksmith runners by workload
* ci: retain static runner capacity supported by utilization
* ci: retain observational runner for peak CPU and memory demand
* ci: restore Windows build to 16 vCPU after runtime regression
* ci: trial 4-vCPU runtime packaging to reduce CPU time allocation
* ci: trial 2-vCPU Linux packaging and serial Windows tests
* ci: include Windows packaging in 2-vCPU trial
The managed-scope disposal cases in subprocess-local and bash-sandbox run past
the 5000ms default when this lane's four partitions, six workers per gate, and
sibling gates share one host. The same commit stays inside the budget on the
in-house pool: the hosted image exceeded it (run 34449848541) and the lane is
green with 90000 (run 34457655892). The Windows coverage lane already grants
the same budget for the same class of teardown.
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.