feat: add AI Agents.md (alternative to #1814)

Author: wp99cp

.github/AGENTS.md

@@ -0,0 +1,77 @@
+# AI Agent Instructions
+
+This document provides a quick reference for AI agents working on the Kleinkram project. For detailed information, always refer to the official documentation in the `../docs/` directory.
+
+## 🚀 Quick Start (Launch)
+
+To launch the full application stack:
+
+```bash
+docker compose up -d
+```
+
+**Access Points:**
+
+- **API Server**: [http://localhost:3000](http://localhost:3000)
+- **Frontend**: [http://localhost:8003](http://localhost:8003)
+- **MinIO Console**: [http://localhost:9001](http://localhost:9001)
+- **Documentation**: [http://localhost:4000](http://localhost:4000)
+
+> [!NOTE]
+> See [../docs/development/getting-started.md](../docs/development/getting-started.md) for detailed setup instructions.
+
+## 🛠️ Development Workflow
+
+### API Interaction
+
+**IMPORTANT**: All API calls to the backend must include the `kleinkram-client-version` header matching the current app version (e.g., `0.56.0`).
+
+```typescript
+headers: {
+    'kleinkram-client-version': '0.56.0', // Replace with actual version from package.json
+    ...
+}
+```
+
+### Formatting & Linting
+
+Run these commands before submitting changes:
+
+```bash
+# Format Python code
+black .
+
+# Format TypeScript/JavaScript/JSON/Markdown
+yarn run prettier
+
+# Run Linting
+yarn run eslint-full:quiet
+```
+
+### Testing
+
+**Backend Tests:**
+
+```bash
+# Run all tests
+yarn test
+
+# Run specific test file
+npx jest tests/actions/action-file-events.test.ts --runInBand --detectOpenHandles --forceExit
+```
+
+**CLI/Python Tests:**
+
+```bash
+# Run pytest (ensure virtualenv is active)
+pytest
+```
+
+> [!NOTE]
+> See [../docs/development/testing/getting-started.md](../docs/development/testing/getting-started.md) for detailed testing guide.
+
+## 📚 Documentation Reference
+
+- **General Setup**: [../docs/development/getting-started.md](../docs/development/getting-started.md)
+- **Testing**: [../docs/development/testing/getting-started.md](../docs/development/testing/getting-started.md)
+- **Python/CLI**: [../docs/development/python/getting-started.md](../docs/development/python/getting-started.md)