docs(P21): rewrite README + normalize modules terminology (REQ-52,55,56,57,58,59,60)

---ci---
project: acdl
phase: 21
milestone: v1.6
status: execute
---/ci---

README.md rewrite:
- Remove all .ciagent/ references (links + repository-layout row).
- Remove .gitea/workflows/ row from repository layout.
- Restate repository roles: consumer repo = app code + 1+ contracts +
  CI definitions (thin .github/workflows/*.yml uses:-ing the central
  workflow); platform repo owns modules/adapters/core/schemas/pipelines/
  scripts/workflows.
- Replace Status section with Features list (consumer + platform-engineer
  referenceable) + Roadmap (planned only, no version changelog, no
  internal CIAgent status). Includes the composition-redesign roadmap
  entry (dynamic module creation from a contract).
- Fix the mermaid flowchart: all node text visible (short multi-line
  labels via <br/>), add a security-checks stage before policy checks,
  do not name specific tools (security checks/policy checks/infrastructure
  plan via adapter), add infrastructure-apply stage (dev only, after
  evidence event).
- Remove the environments table (dev/qa/prod/dr) completely; point to
  docs/environments/ for platform-managed environments.
- Credentials section: remove go-gitea/gitea#36988 blocked mention +
  waivers D-039/D-047 language. State OIDC+ABAC default; alternative is a
  static AWS key (GitHub Secrets for platform-runner runs, .env.secrets
  locally) with daily rotation (platform-managed) or out-of-band rotation
  (consumer-managed for local .env.secrets).
- forge -> platform runners / platform-managed throughout.
- Links point to docs/ Pages paths, not .ciagent/.

modules/ terminology:
- modules/README.md: L1 primitives -> primitives, L2 compositions ->
  modules, composition -> pattern (prose); add roadmap note for the
  composition redesign.
- README-TEMPLATE.md: L1 primitive -> primitive.
- All 7 L1 READMEs: L1 primitive -> primitive.
- L2 static-asset + microservice READMEs: L2 composition -> module
  pattern, composition -> pattern, L1 -> primitive; bump stale @v1 ->
  @v1.4 in usage examples; fix CONSUMER_GUIDE.md -> consumer-guide.md
  link.

Verification: grep sweeps for .ciagent/.gitea/forge/go-gitea/waiver/
D-039/D-047/acdl_platform in docs/ README.md modules/ contracts/ all
return 0 hits. Tests: 166 pass. run_ci.sh green.

modules/README.md

@@ -8,19 +8,19 @@ self-documented with a `README.md` following the
 
 There are two kinds of module:
 
-- **L1 primitives** — a single cloud resource or a small group of
-  related resources (e.g. a VPC with subnets and routing). Each L1 has
-  an `interface.json` declaring its inputs and outputs, and a `README.md`
-  in plain language.
-- **L2 compositions** — a composition that references multiple L1s to
-  deploy a complete stack (e.g. an ECS Fargate microservice). Each L2
+- **Primitives** — a single cloud resource or a small group of
+  related resources (e.g. a VPC with subnets and routing). Each primitive
+  has an `interface.json` declaring its inputs and outputs, and a
+  `README.md` in plain language.
+- **Modules** — a pattern that references multiple primitives to
+  deploy a complete stack (e.g. an ECS Fargate microservice). Each module
   has a `composition.json` declaring its children and wires.
 
-The Terraform adapter (`adapters/terraform/adapter.py`) compiles a
-module instance to Terraform. Each module's README documents which
-Terraform resources it creates.
+The substrate adapter (`adapters/terraform/adapter.py`) compiles a
+module instance to infrastructure. Each module's README documents which
+resources it creates.
 
-## L1 primitives
+## Primitives
 
 | Module | What it creates | README |
 |--------|----------------|--------|
@@ -32,19 +32,26 @@ Terraform resources it creates.
 | `alb` | `aws_lb` + `aws_lb_target_group` + `aws_lb_listener` — Application Load Balancer | [README](l1/alb/README.md) |
 | `ecr` | `aws_ecr_repository` — ECR container image repository | [README](l1/ecr/README.md) |
 
-## L2 compositions
+## Modules
 
 | Module | What it references | README |
 |--------|--------------------|--------|
-| `microservice` | 6 L1s (vpc, cluster, ecr, iam-role, alb, ecs-service) | [README](l2/microservice/README.md) |
-| `static-asset` | 1 L1 (s3) | [README](l2/static-asset/README.md) |
+| `microservice` | 6 primitives (vpc, cluster, ecr, iam-role, alb, ecs-service) | [README](l2/microservice/README.md) |
+| `static-asset` | 1 primitive (s3) | [README](l2/static-asset/README.md) |
 
 ## Registry
 
-Module versions are tracked in `registry.json`. Both L1 and L2 entries
-are registered.
+Module versions are tracked in `registry.json`. Both primitives and
+modules are registered.
 
 ## Template
 
 New modules should use [README-TEMPLATE.md](README-TEMPLATE.md) as
-their starting point.
+their starting point.
+
+## Module patterns (roadmap)
+
+The current `composition.json` mechanism is a thin pattern layer. A future
+redesign will let a consumer dynamically create a module directly from the
+contract file (an agentic "composition" flow). That is on the roadmap, not
+implemented today.