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/action.yml

@@ -1,5 +1,6 @@
 # tinqs/ci/setup-aws — Tinqs Studio CI
 # Installs AWS CLI and optionally logs into ECR.
+# Detects Alpine (musl) vs Debian (glibc) and uses the right install method.
 # Credentials come from the runner environment (IAM task role on Fargate, instance
 # profile on EC2/Lightsail) — no explicit key configuration needed.
 # Composite action — runs directly on the host.
@@ -30,10 +31,20 @@ runs:
         # Install AWS CLI if missing
         if ! command -v aws &>/dev/null; then
           echo "Installing AWS CLI..."
-          curl -fsSL https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip -o /tmp/awscli.zip
-          unzip -q /tmp/awscli.zip -d /tmp/aws-install
-          /tmp/aws-install/aws/install
-          rm -rf /tmp/awscli.zip /tmp/aws-install
+          if command -v apk &>/dev/null; then
+            # Alpine — use pip (AWS CLI v2 binary needs glibc)
+            apk add --no-cache python3 py3-pip
+            pip3 install --break-system-packages awscli 2>/dev/null || pip3 install awscli
+          elif command -v apt-get &>/dev/null; then
+            # Debian/Ubuntu — use official installer
+            apt-get update && apt-get install -y unzip curl
+            curl -fsSL https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip -o /tmp/awscli.zip
+            unzip -q /tmp/awscli.zip -d /tmp/aws-install
+            /tmp/aws-install/aws/install
+            rm -rf /tmp/awscli.zip /tmp/aws-install
+          else
+            echo "ERROR: unsupported package manager" && exit 1
+          fi
         fi
 
         aws --version