feat(P27): add Examples section to every module README (D-058)

Each module README (10 primitives + 2 patterns) now has a ## Examples
section before ## Versioning, referencing and excerpting the validated
simple.yaml + complex.yaml (+ mysql.yaml for RDS) example contracts. The
RDS README includes a Multi-engine variation subsection (D-059).

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

modules/l1/waf/README.md

@@ -60,6 +60,43 @@ composition (see `modules/l2/static-assets`).
 - **Logging** — enable WAF access logging to S3/CloudWatch/Kinesis for
   auditability (SOC2 CC7.2, DORA audit trail).
 
+## Examples
+
+Validated example contracts are in [`examples/`](examples/). The platform-test
+pipeline validates them against `schemas/contract.schema.json`.
+
+### Simple
+
+A minimal deployment:
+
+[`examples/simple.yaml`](examples/simple.yaml)
+```yaml
+# Simple WAF with managed rules only
+uses: acdl/pipelines/deploy.yaml@v1.6
+module: waf
+environment: dev
+inputs:
+  name: my-waf
+  region: us-east-1
+```
+
+### Complex
+
+A production deployment with optional inputs:
+
+[`examples/complex.yaml`](examples/complex.yaml)
+```yaml
+# Complex WAF with rate limiting + geo blocking (custom rules)
+uses: acdl/pipelines/deploy.yaml@v1.6
+module: waf
+environment: dev
+inputs:
+  name: my-production-waf
+  scope: cloudfront
+  default_action: allow
+  region: us-east-1
+```
+
 ## Versioning
 
 `1.0.0` — interface MAJOR, behavior MINOR, lifecycle PATCH. MAJOR bumps