Cognitect Anomalies - standardized error categories.

Based on https://github.com/cognitect-labs/anomalies

Anomalies are maps with ::category key indicating the error type.
These map to HTTP status codes:

| Category      | HTTP | Description                                    |
|---------------|------|------------------------------------------------|
| ::unavailable | 503  | Service temporarily unavailable, retry later   |
| ::interrupted | 500  | Operation was interrupted                      |
| ::incorrect   | 400  | Bad request, invalid input                     |
| ::forbidden   | 403  | Not authorized to perform this action          |
| ::unauthorized| 401  | Authentication required                        |
| ::not-found   | 404  | Resource not found                             |
| ::conflict    | 409  | Conflict with current state (e.g., duplicate)  |
| ::fault       | 500  | Internal server error                          |
| ::busy        | 503  | Server is busy, retry later                    |
| ::unsupported | 501  | Operation not supported                        |

Usage:
(throw! ::forbidden "You are not authorized to access this resource")
(throw! ::not-found "Therapy plan not found" {:plan-id plan-id})
(throw! ::incorrect "Invalid email format" {:field :email})