AWS Braket backend implementation for QClojure quantum computing library.

This namespace provides a backend that connects QClojure to Amazon Braket
quantum computing services, supporting both simulators and quantum hardware
devices.

Functions for managing and querying AWS Braket quantum devices, including QPUs and simulators.

Functions for calculating pricing for quantum jobs on AWS Braket.

This namespace provides cost estimation for quantum circuits based on
actual device pricing data from AWS Braket device capabilities.

Pricing models:
- QPU devices: flat per-task fee ($0.30) + per-shot fee (device-specific)
- Simulators: per-minute fee (device-specific), estimated from circuit complexity

Pricing data sources (in order of preference):
1. Device capabilities from GetDevice API (:capabilities -> :service -> :device-cost)
2. AWS Pricing API (fallback)
3. Hardcoded fallback values (last resort)

The per-shot prices vary by device and are available in the device capabilities
map under [:service :device-cost {:price <number> :unit <string>}].
The per-task fee of $0.30 is uniform across all QPUs.

Functions for managing quantum jobs on AWS Braket.