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-go/action.yml

@@ -1,11 +1,12 @@
 # tinqs/ci/setup-go — Tinqs Studio CI
 # Downloads Go from go.dev and adds it to PATH.
+# Works on any Linux (Alpine, Debian, etc.) — just a tarball extract.
 # Skips install if the correct version is already present (pre-baked runner image).
 # Composite action — runs directly on the host.
 # Author: Ozan + Claude Code — 2026-05-22
 
 name: 'Tinqs Setup Go'
-description: 'Install Go and configure PATH (replaces actions/setup-go)'
+description: 'Install Go and configure PATH'
 
 inputs:
   go-version:
@@ -20,7 +21,7 @@ runs:
 
         # Skip if already installed at correct version
         if command -v go &>/dev/null; then
-          CURRENT=$(go version | grep -oP '\d+\.\d+\.\d+' || true)
+          CURRENT=$(go version | sed 's/.*go//' | cut -d' ' -f1)
           if [ "$CURRENT" = "$GO_VERSION" ]; then
             echo "Go $GO_VERSION already installed"
             go version