feat(P02 W0): dynamodb L1 primitive — interface, terraform, registry, tests (REQ-322)

New L1 module modules/l1/dynamodb/ (stack type aws:dynamodb:table).
Terraform aws_dynamodb_table with PK + optional SK, PAY_PER_REQUEST
default, SSE-KMS + PITR + prevent_destroy per v1.8 NFR defaults.
Registry entry (kind l1), catalog row, test_adapter.py updated to
15 entries / 13 L1. 45 tests passing.

---ci---
project: acdl
phase: 2
milestone: v1.26
status: execute
phase_role: execution
wave: 0
requirements: [REQ-322]
---/ci---

modules/l1/dynamodb/README.md

@@ -0,0 +1,38 @@
+# DynamoDB L1 Primitive
+
+> Stack type: `aws:dynamodb:table` → Terraform `aws_dynamodb_table`
+
+## Description
+
+A DynamoDB table primitive with encryption + point-in-time recovery
+enabled by default (per v1.8 NFR defaults). Supports a partition key
+(required) + optional sort key. Default billing mode is
+`PAY_PER_REQUEST` (on-demand).
+
+## Inputs
+
+| Name | Type | Required | Default | Description |
+|---|---|---|---|---|
+| `table_name` | string | yes | — | Globally-unique table name |
+| `region` | string | yes | — | AWS region |
+| `pk` | string | yes | — | Partition key attribute name |
+| `sk` | string | no | `""` | Sort key attribute name |
+| `billing_mode` | string | no | `PAY_PER_REQUEST` | Billing mode |
+| `enabled` | boolean | no | `true` | Feature flag |
+
+## Outputs
+
+| Name | Type | Description |
+|---|---|---|
+| `table_arn` | arn | The table ARN |
+| `table_name` | string | The table name |
+
+## NFRs
+
+- **Encryption:** SSE-KMS enabled by default.
+- **Point-in-time recovery:** Enabled by default.
+- **Deletion protection:** `prevent_destroy = true` (Terraform lifecycle).
+
+## Examples
+
+See `examples/simple.yaml`.