Initial release of CHORUS Development Images

This commit establishes the foundation for language-specific development
container images used by CHORUS autonomous agents.

Features:
- Multi-stage Dockerfile with 7 layered images
- Base Debian Bookworm image with common tools
- Language-specific images: Rust, Go, Python, Node.js, Java, C/C++
- Standardized /workspace/{input,data,output} structure
- Automated CI/CD pipeline for weekly security updates
- Comprehensive test suite for all images
- Full documentation (README, USAGE, MAINTENANCE)

Images available:
- chorus/base:1.0.0 (~200MB)
- chorus/rust-dev:1.0.0 (~1.2GB)
- chorus/go-dev:1.0.0 (~600MB)
- chorus/python-dev:1.0.0 (~800MB)
- chorus/node-dev:1.0.0 (~700MB)
- chorus/java-dev:1.0.0 (~1.5GB)
- chorus/cpp-dev:1.0.0 (~900MB)

🤖 Generated with Claude Code (https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

images/base/entrypoint.sh

@@ -0,0 +1,27 @@
+#!/bin/bash
+# CHORUS Development Environment Entrypoint
+# Provides standardized initialization for development containers
+
+set -e
+
+# Display workspace structure on first run
+if [ ! -f "${WORKSPACE_DATA}/.chorus-initialized" ]; then
+    cat << "EOF"
+╔════════════════════════════════════════════════════════════════╗
+║           CHORUS Development Environment                       ║
+╚════════════════════════════════════════════════════════════════╝
+
+Workspace Structure:
+  📂 /workspace/
+    ├── input/   - Task requirements, repository checkout
+    ├── data/    - Working directory, build artifacts
+    └── output/  - Deliverables, patches, reports
+
+Current Directory: /workspace/data
+
+EOF
+    touch "${WORKSPACE_DATA}/.chorus-initialized"
+fi
+
+# Execute provided command or shell
+exec "$@"