feat(docker): pre-install essential dev tools in minimal image

Add commonly used development tools to the minimal Dockerfile:
- curl: HTTP requests and health checks
- jq: JSON processing
- git: Version control for skills
- python3 + py3-pip: Python script support
- bash: Better shell scripting support

These tools are essential for many PicoClaw skills and MCP tools
to function properly in containerized environments.

Fixes #1228

docker/Dockerfile

@@ -20,7 +20,15 @@ RUN make build
 # ============================================================
 FROM alpine:3.23
 
-RUN apk add --no-cache ca-certificates tzdata curl
+RUN apk add --no-cache \
+  ca-certificates \
+  tzdata \
+  curl \
+  jq \
+  git \
+  python3 \
+  py3-pip \
+  bash
 
 # Health check
 HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \