test: raise the contended Windows spawn budgets to 90s

The per-case 15-30s budgets on the Windows native and coverage lanes fire
before oxlint, workflow-worker-thread, and other subprocess-spawning cases
finish under the loaded self-hosted pool; the failures rotate across cases
as load shifts, so per-case widening only moved the flake. Raise the lane
defaults (DSH_COVERAGE_TEST_TIMEOUT_MS and the native --testTimeout) to 90s,
align the oxlint and workflow-worker-thread case budgets, and keep the
built-bin SPAWN_TIMEOUT_MS at 60s under a 90s outer budget.

.github/workflows/ci.yml

@@ -446,7 +446,7 @@ jobs:
     env:
       DSH_COVERAGE_MAX_WORKERS: '6'
       DSH_COVERAGE_PARTITIONS: '4'
-      DSH_COVERAGE_TEST_TIMEOUT_MS: '30000'
+      DSH_COVERAGE_TEST_TIMEOUT_MS: '90000'
       DSH_GATE_CONCURRENCY: '3'
     steps:
       - uses: actions/checkout@v6
@@ -505,7 +505,7 @@ jobs:
         run: >-
           pnpm exec vitest run
           --no-file-parallelism
-          --testTimeout 30000
+          --testTimeout 90000
           packages/shell/tool-pwsh/tests/loader.spec.ts
           packages/workflow/workflow-worker-thread/tests/workflow-worker-thread.spec.ts
           packages/workflow/tool-ralph/tests/integration.spec.ts