feat(P27): validated per-module examples (D-058) + schema glob fix

Add modules/<name>/examples/ directories with simple.yaml + complex.yaml
(+ mysql.yaml for RDS) for every primitive and module pattern. All 25
example contracts validate against schemas/contract.schema.json. Update
the contract schema to allow object/array input values (for env vars).
Fix the platform-test schema-validation glob to modules/*/*/examples/*.yaml
to match the nested l1/l2 path structure. Update the microservice sample
contract note (env objects now permitted by the schema).

---ci---
project: acdl
phase: 27
milestone: v1.7
status: execute
---/ci---

.github/workflows/platform-test.yml

@@ -131,7 +131,7 @@ jobs:
           import json, yaml, glob, jsonschema
           schema = json.load(open('schemas/contract.schema.json'))
           # Validate example contracts if they exist
-          for example in glob.glob('modules/*/examples/*.yaml'):
+          for example in glob.glob('modules/*/*/examples/*.yaml'):
               try:
                   contract = yaml.safe_load(open(example))
                   jsonschema.validate(contract, schema)