Add Deployment REST API endpoints

## Overview

Implement REST API endpoints for Deployment CRUD operations.

## Tasks

1. Create REST endpoints in manager API:
- POST /deployments - Create deployment
- GET /deployments - List deployments (with pagination, filtering)
- GET /deployments/{id} - Get deployment detail
- PATCH /deployments/{id} - Update deployment
- DELETE /deployments/{id} - Delete deployment
1. Implement request validation using DTOs
1. Implement proper error responses
1. Add OpenAPI documentation
1. Write integration tests

## Notes

- Use pydantic DTOs from previous story
- Separate from existing /endpoints API

JIRA Issue: BA-3431