fix(ci): serial-windows notices timeout and generator store-scan cost

render() loaded the workspace manifests once per external dependency
name through workspaceLinkedManifest, an O(names x manifests) file
read on the cold path; on the loaded self-hosted Windows host with
coverage instrumentation the freshness spec crossed Vitest's default
5000ms budget and failed the serial-windows standby gate four times in
a week. Load the manifests once in render() and thread the map through
the collectors instead.

The serial-windows lane also ran the coverage inventory at the strictest
budget of any lane: add DSH_COVERAGE_TEST_TIMEOUT_MS=90000 to match the
pull-request windows-coverage lane, pinned by ci-workflow.spec.ts.

.github/workflows/ci-master.yml

@@ -208,6 +208,7 @@ jobs:
         shell: pwsh
         env:
           DSH_COVERAGE_MAX_WORKERS: '1'
+          DSH_COVERAGE_TEST_TIMEOUT_MS: '90000'
           DSH_GATE_CONCURRENCY: '1'
           DSH_PUBLINT_CONCURRENCY: '1'
         run: pnpm run check:ci:windows-complete