fix: Alpine compatibility + READMEs + roadmap

- setup-node: detect Alpine/Debian, use apk or NodeSource
- setup-aws: use pip on Alpine (musl), binary on Debian (glibc)
- setup-go: fix version parsing for Alpine (no grep -P)
- README per action with usage examples and input docs
- PLAN.md: roadmap for runner images, labels, Lambda dispatch

setup-aws/README.md

@@ -0,0 +1,28 @@
+# tinqs/ci/setup-aws
+
+Installs AWS CLI and optionally logs into ECR.
+
+Detects Alpine (musl) vs Debian (glibc) and uses the right install method — pip on Alpine, official binary on Debian. Credentials come from the runner environment (IAM task role on Fargate, instance profile on EC2).
+
+## Usage
+
+```yaml
+- uses: tinqs/ci/setup-aws@v1
+```
+
+### With ECR login
+
+```yaml
+- uses: tinqs/ci/setup-aws@v1
+  with:
+    ecr-login: 'true'
+    ecr-repo: '149751500842.dkr.ecr.eu-west-1.amazonaws.com/tinqs-git'
+```
+
+## Inputs
+
+| Input | Default | Description |
+|-------|---------|-------------|
+| `region` | `eu-west-1` | AWS region |
+| `ecr-login` | `false` | Login to ECR after install |
+| `ecr-repo` | `` | ECR repository URL (required when ecr-login is true) |