feat: multi-image runners — go, node, docker, deploy, godot

Replace single fat image with purpose-built images per workflow type.
Each image is lean: base (Alpine+AWS+git) → go/node/deploy extend it.
docker image standalone (dind base). godot for future game builds.
build-all.sh builds base first, then all others in parallel.

images/node/Dockerfile

@@ -0,0 +1,13 @@
+# tinqs/ci node — Node.js builds (docs, frontend)
+# Used by: deploy-docs
+# runs-on: node
+
+ARG BASE_IMAGE=tinqs-runner-base:latest
+FROM ${BASE_IMAGE}
+
+ARG NODE_VERSION=22
+
+RUN apk add --no-cache nodejs npm && \
+    npm install -g pnpm
+
+RUN node --version && pnpm --version