Claude Code: Add network retry and fault tolerance to Dockerfile

- Add --retry-on-error to apt-get update
- Add retry wrapper to git clone for A2A gateway
- Add --no-cache-dir to npm install for A2A gateway

Dockerfile

@@ -22,7 +22,7 @@ ARG NODE_ENV=production
 # ── System dependencies (root) ───────────────────────────────────────────────
 # Optimization: Install Python and system deps in minimal layers for caching
 RUN echo "[build] Installing system dependencies..." && START=$(date +%s) \
-  && apt-get update \
+  && apt-get update --retry-on-error \
   # Minimal install: git for cloning, ca-certificates for HTTPS, curl for health checks
   && apt-get install -y --no-install-recommends \
     git \
@@ -90,10 +90,12 @@ WORKDIR /app
 # ── A2A Gateway Extension ───────────────────────────────────────────────────
 # Install extension as non-root user
 RUN echo "[build] Installing A2A gateway..." && START=$(date +%s) \
-  && git clone --depth 1 https://github.com/win4r/openclaw-a2a-gateway.git \
-    /app/openclaw/extensions/a2a-gateway \
+  && (git clone --depth 1 https://github.com/win4r/openclaw-a2a-gateway.git \
+      /app/openclaw/extensions/a2a-gateway || \
+    (sleep 5 && git clone --depth 1 https://github.com/win4r/openclaw-a2a-gateway.git \
+      /app/openclaw/extensions/a2a-gateway)) \
   && cd /app/openclaw/extensions/a2a-gateway \
-  && npm install --production \
+  && npm install --production --no-cache-dir \
   && echo "[build] A2A gateway: $(($(date +%s) - START))s"
 
 # ── Coding Agent Extension (local — no git clone needed) ─────────────────────