test: regression coverage for schema sync #874 (istio routing, NotificationRules)

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Description

Adds contract tests for upstream schema changes synced in auto-sync PR #874.

Triggered by: PR #874 (chore: auto-sync harness schemas)

Risky behavior now covered

• K8sTrafficRoutingSpec provider enum in v0 pipeline and template bundles — upstream removed the deprecated smi provider; only istio remains. Without a contract test, a bad sync could silently reintroduce smi or drop the istio conditional $ref.
• IstioProviderSpec shape — upstream consolidated SMI/Istio provider specs; agents using harness_schema must see gateways, hosts, and delegateService (not the removed rootService / SMIProviderSpec).
• Pipeline template allowedOverrides — upstream added NotificationRules so template consumers can override notification config; a dropped enum entry would break valid template YAML.

Test files added/updated

• tests/schemas/schema-bundle-contract.test.ts — three new cases:
  • drops the removed smi provider from K8sTrafficRoutingSpec in v0 pipeline and template
  • includes upstream IstioProviderSpec traffic-routing fields in v0 pipeline and template
  • includes NotificationRules in pipeline template allowedOverrides

Why these tests materially reduce regression risk

Schema auto-sync PRs are high-volume and low-review. CD traffic-routing and template override enums are easy to regress during upstream merges (duplicate definitions, stale provider enums). These follow the existing bundle-contract pattern used for other upstream step additions.

Validation

• pnpm test tests/schemas/schema-bundle-contract.test.ts — 19/19 passed

Type of Change

• Bug fix
• New feature
• Refactor
• Documentation
• Other — regression test coverage

Checklist

• pnpm test passes (targeted: schema bundle contract)
• pnpm typecheck passes
• pnpm build passes
• pnpm standards:check passes
• pnpm docs:check passes

Note

This branch includes the #874 schema sync commit so tests pass in CI. Merge after or in place of #874; only the test commit is net-new coverage.