refactor(P57): contract surface redesign + rename + .yml repo-wide

Contract surface redesign:
- New top-level fields: id (3-6 char acronym → stack.name), name (full → stack.title),
  infrastructure (map keyed by module name, replaces module:)
- Drop uses: field (dead reference; version pin lives in CI workflow uses: line)
- Drop top-level module/inputs (now nested under infrastructure map)
- Per-module optional version (defaults to latest published from registry)
- Multi-module contracts: one file deploys N modules in one pipeline run,
  resource IDs namespaced with module name to avoid collisions
- stack.schema.json: add optional title field for display name

Rename:
- pipelines/deploy.yaml → pipelines/contract.yml (declarative spec, not a pipeline)
- pipelines/ci.yaml → pipelines/ci.yml
- All 44 .yaml files → .yml repo-wide (contracts, module examples, kyverno policies)
- .acdl/contract.yaml → .acdl/contract.yml

Resolver (core/contract_resolver.py):
- Rewrite resolve() to loop infrastructure map, default version to latest,
  merge module fragments into one stack with namespaced resource IDs
- _latest_version() picks highest non-deprecated from registry
- _namespace_resources() prefixes IDs + rewrites ref: expressions for multi-module
- Single-module path: unprefixed IDs (backward compatible)

Verification:
- 494 tests pass (0 contract-shape failures)
- Local E2E passes (contract → resolver → adapter → local ECS HTTP 200 → outbox)

---ci---
project: acdl
phase: 57
milestone: v1.10.2
status: execute
---/ci---

adapters/kyverno/README.md

@@ -53,12 +53,12 @@ invoke it. The `engine: "kyverno"` enum value is present in
 The `policies/` directory holds three valid Kyverno `ClusterPolicy`
 manifests (documentation-only today — the platform does not run them):
 
-- `disallow-privileged-containers.yaml` — fail pods with
+- `disallow-privileged-containers.yml` — fail pods with
   `securityContext.privileged: true`.
-- `require-resource-labels.yaml` — require `acdl:owner` and
+- `require-resource-labels.yml` — require `acdl:owner` and
   `acdl:environment` labels on all pods (mirrors the ACDL tagging standard
   in [`schemas/tagging-standard.json`](../../schemas/tagging-standard.json)).
-- `require-image-digests.yaml` — require container images to reference a
+- `require-image-digests.yml` — require container images to reference a
   digest (`image@sha256:...`), not a mutable tag.
 
 ## Schema path