feat: add Node.js to all runner images (golang, rust, node)

- Dockerfile.golang: docker:27-cli + Node.js + build tools
- Dockerfile.rust: docker:27-cli + Node.js + Rust + build tools
- Dockerfile.node: node:22-bookworm + docker.io (already has Node.js)
- All runners now support GitHub Actions (checkout@v4 requires Node.js)
- Images built/pushed manually (no CI for homelab)

To build and push:
  docker build -f k8s/infra/forgejo-runner/Dockerfile.golang \
    -t forgejo.riotpiao.com/rock/forgejo-runner-golang:latest .
  docker build -f k8s/infra/forgejo-runner/Dockerfile.rust \
    -t forgejo.riotpiao.com/rock/forgejo-runner-rust:latest .
  docker build -f k8s/infra/forgejo-runner/Dockerfile.node \
    -t forgejo.riotpiao.com/rock/forgejo-runner-node:latest .

  docker push forgejo.riotpiao.com/rock/forgejo-runner-golang:latest
  docker push forgejo.riotpiao.com/rock/forgejo-runner-rust:latest
  docker push forgejo.riotpiao.com/rock/forgejo-runner-node:latest

k8s/infra/forgejo-runner/Dockerfile.rust

@@ -0,0 +1,20 @@
+FROM docker:27-cli
+
+# Install Node.js + build essentials (needed for GitHub Actions checkout@v4, etc.)
+RUN apt-get update && \
+    apt-get install -y --no-install-recommends \
+      nodejs \
+      npm \
+      git \
+      curl \
+      ca-certificates \
+      build-essential \
+      python3 && \
+    rm -rf /var/lib/apt/lists/*
+
+# Install Rust
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y && \
+    . $HOME/.cargo/env
+
+# Verify installations
+RUN docker --version && node --version && git --version && rustc --version