ci(required-gate): pr-contract failure fail-fast-skips all language CI lanes

[ArchonVII]

Summary

In the reusable repo-required-gate.yml, every downstream lane (node-ci, go-ci, python-ci, workflow-validation, policy-validation, dependency-review, snapshot-validation) is gated on PR-contract success via:

needs: [detect, pr-contract]
if: ... && (github.event_name != 'pull_request' || inputs.run-pr-contract == false || needs.pr-contract.result == 'success')

When a PR body fails the contract, pr-contract fails, and that clause makes every lane skip. The decision job then requires node ci == success, sees skipped, and emits a misleading node ci ... required but result was skipped — while no real CI ever ran. A malformed PR body therefore silently suppresses all validation.

Impact

Consumers pinned to @v1 admin-merged PRs without real CI signal. Surfaced downstream as ArchonVII/archon#200; Archon worked around it locally (run-pr-contract: false + a sibling contract job) in ArchonVII/archon#202, but the defect lives here at the source.

Fix

Decouple the lanes from the contract: lanes depend on detect alone; the decision job stays the single aggregator that requires both the contract and the lanes. A bad body still blocks merge — now with real lane signal instead of a phantom skip.

Rollout

After merge, advance the moving v1 tag to the merged commit so consumers pinned to @v1 pick up the fix.