Add Swagger documentation for user routes

[cyber-shehan]

This PR adds Swagger/OpenAPI documentation for the User Service routes to improve API documentation and make the endpoints easier to understand and test through Swagger UI.

The documentation includes:
• Endpoint summaries and descriptions.
• Appropriate tags for grouping endpoints.
• Bearer authentication requirements for protected endpoints.
• Path parameter documentation where applicable.
• Response documentation for successful and error responses.

Swagger annotations were added to the route definitions to generate the API documentation.

Documented Endpoints

Health
• GET /api/users/health

Metadata
• GET /api/users/meta/locations
• GET /api/users/meta/event-statuses
• GET /api/users/meta/linked-event-types
• GET /api/users/meta/seasons
• GET /api/users/meta/reference-days
• GET /api/users/meta/reference-times

Integration
• GET /api/users/integration
• GET /api/users/integration/{integrationId}
Training Models
• GET /api/users/training-models
• GET /api/users/training-models/{file_id}

Users
• GET /api/users/user

Dashboard
• GET /api/users/dashboard/overview
• GET /api/users/dashboard/charts
• GET /api/users/dashboard/activity

Hazards
• GET /api/users/hazards
• GET /api/users/hazards/{hazardId}

Testing
• Verified that all documented endpoints are displayed correctly in Swagger UI.
• Tested the documentation locally using:
◦ npm run dev:gateway
◦ npm run dev:user
• Confirmed that protected endpoints correctly require authentication and return401 Unauthorized when accessed without a valid token.

Notes
This PR only adds Swagger/OpenAPI documentation and related Swagger annotations. No business logic or endpoint behaviour was intentionally modified.