[Change] Attach test and repro log artifacts to PR orchestrator runs

[djm81]

Why

The current GitHub Action runner (.github/workflows/pr-orchestrator.yml) forces us to copy-paste from the UI when debugging; error details are often truncated or only snippets are visible, so we must re-run the full suite locally to find all issues. Repro test output and reports are not attached to the run. The goal is to attach test and repro log artifacts to each CI run so we can download them on failure and shift full validation to CI before merging to dev.

What Changes

• Tests job: Use hatch run smart-test-full so full test and coverage logs are written under logs/tests/, and upload those logs as workflow artifacts.
• Contract-first-ci job (repro): Capture repro stdout/stderr to a file under logs/repro/ and upload repro logs plus .specfact/reports/enforcement/ as artifacts.
• Documentation: Update docs to describe CI log artifacts and how to download and use them.

Acceptance Criteria

• Tests job runs smart-test-full and uploads logs/tests/ as artifact (e.g. test-logs).
• Contract-first-ci job captures repro output to logs/repro/ and uploads repro-logs and repro-reports artifacts.
• Docs describe where to find and how to use test and repro log artifacts.

OpenSpec Change Proposal: ci-01-pr-orchestrator-log-artifacts