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---

tests/test_module_standards.py

@@ -28,8 +28,8 @@ class TestModuleStandards:
             assert (l1_dir / "interface.json").is_file(), f"{name}: interface.json missing"
             assert (l1_dir / "instance.json").is_file(), f"{name}: instance.json missing"
             assert (l1_dir / "README.md").is_file(), f"{name}: README.md missing"
-            assert (l1_dir / "examples" / "simple.yaml").is_file(), f"{name}: examples/simple.yaml missing"
-            assert (l1_dir / "examples" / "complex.yaml").is_file(), f"{name}: examples/complex.yaml missing"
+            assert (l1_dir / "examples" / "simple.yml").is_file(), f"{name}: examples/simple.yml missing"
+            assert (l1_dir / "examples" / "complex.yml").is_file(), f"{name}: examples/complex.yml missing"
 
     def test_all_l2_have_required_files(self, registry):
         for name, entry in registry.items():
@@ -39,8 +39,8 @@ class TestModuleStandards:
             l2_dir = ROOT / "modules" / "l2" / name
             assert (l2_dir / "composition.json").is_file(), f"{name}: composition.json missing"
             assert (l2_dir / "README.md").is_file(), f"{name}: README.md missing"
-            assert (l2_dir / "examples" / "simple.yaml").is_file(), f"{name}: examples/simple.yaml missing"
-            assert (l2_dir / "examples" / "complex.yaml").is_file(), f"{name}: examples/complex.yaml missing"
+            assert (l2_dir / "examples" / "simple.yml").is_file(), f"{name}: examples/simple.yml missing"
+            assert (l2_dir / "examples" / "complex.yml").is_file(), f"{name}: examples/complex.yml missing"
 
     def test_all_l1_have_deletion_protection_nfr(self, registry):
         for name, entry in registry.items():