feat: Add development scripts for environment check and service management

- check-env.sh: Validates Python 3.10+, Node.js, Docker, venv, .env, ports
- start-dev.sh: Starts MinIO, backend, frontend with health checks
- stop-dev.sh: Gracefully stops all services

Scripts are placed in project root for easy access.
Supports --help flag and colored output.

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

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

openspec/changes/archive/2025-12-01-add-dev-scripts/proposal.md

@@ -0,0 +1,28 @@
+# Change: Add Development Scripts
+
+## Why
+Developers currently need to manually start multiple services (MinIO, backend, frontend) and verify environment prerequisites before running the application. This is error-prone and time-consuming. Automated scripts will streamline the development workflow and reduce onboarding friction.
+
+## What Changes
+- **NEW**: Environment check script (`check-env.sh`) - Validates all prerequisites
+- **NEW**: Unified development startup script (`start-dev.sh`) - Starts all services
+- **NEW**: Stop script (`stop-dev.sh`) - Gracefully stops all services
+
+## Impact
+- Affected specs: Creates new `dev-scripts` specification
+- Affected code:
+  - Shell scripts in project root directory
+  - No changes to existing application code
+
+## Dependencies
+- Existing docker-compose.minio.yml for MinIO
+- Python virtual environment (venv/)
+- Node.js and npm for frontend
+
+## Success Criteria
+1. `check-env.sh` validates Python 3.10+, Node.js, Docker, required ports
+2. `check-env.sh` provides clear error messages for missing prerequisites
+3. `start-dev.sh` starts MinIO, backend, and frontend in correct order
+4. `start-dev.sh` waits for each service to be healthy before proceeding
+5. `stop-dev.sh` gracefully terminates all services
+6. Scripts work on Linux/WSL environments