docs(P20): specify phase 20 — consumer happy path + reusable deploy workflow (v1.5)

---ci---
project: acdl
phase: 20
milestone: v1.5
status: specify
---/ci---

Add v1.5 milestone to ROADMAP.md + REQUIREMENTS.md. Phase 20 covers
REQ-46 (README consumer model + mermaid + L3B/spike scrub), REQ-47
(generic CONSUMER_GUIDE.md + versioned uses: + consumer-scoped prereqs
+ run-time platform fetch), REQ-48 (zero-trust OIDC/ABAC credentials +
static-key override + daily rotation), REQ-49 (reusable byte-identical
deploy.yml Gitea+GitHub implementing pipelines/deploy.yaml), REQ-50
(contracts/static-asset.yaml @v1.4), REQ-51 (deploy-workflow conformance
tests). Update config.json milestone to v1.5.

modules/l1/s3/instance.json

@@ -0,0 +1,23 @@
+{
+  "version": "1.0.0",
+  "stack": {
+    "name": "l1-s3",
+    "kind": "l1",
+    "depth": 1
+  },
+  "resources": [
+    {
+      "id": "s3",
+      "type": "aws:s3:bucket",
+      "module": "l1-s3@1.0.0",
+      "inputs": {
+        "bucket_name": "acdl-spike-bucket",
+        "region": "us-east-1"
+      },
+      "outputs": {
+        "bucket_arn": {"type": "arn", "description": "The S3 bucket ARN."},
+        "bucket_name": {"type": "string", "description": "The bucket name."}
+      }
+    }
+  ]
+}