[ops]: harden trusted pilot routing outputs

[svelderrainruiz]

Summary

• remove the trusted pilot path filter from the router
• replace Out-File -Encoding utf8 output writes with Add-Content
• make trusted pilot routing observable in step summary and gate on fromJSON(...)

Why

The direct operator proof on the mounted integration baseline showed that workflow_dispatch reached trust-context but still admitted the skipped job instead of the pilot job. The integration proving rail also showed the additive pilot disappearing on the trusted PR surface even after mounting the evidence fix. This slice makes the routing contract observable and removes two likely sources of silent false negatives: path filtering and fragile string-based output handling.

Evidence

• standing issue: [ops]: refactor Pester into a readiness/execution/evidence service model #2069
• operator proof run: 23805747866
• local proof:
  • node --test tools/priority/__tests__/pester-service-model-workflow-contract.test.mjs
  • git diff --check