v1.7.0a2

Improve noise-suppression portability, extend Python compatibility, and strengthen the test and CI workflow.

New Features:

• Replace the PyTorch-based DeepFilterNet noise-suppression backend with the ONNX-based DPDFNet implementation in the optional full extra.
• Raise the minimum Python version to 3.11, add Python 3.13 and 3.14 support, and refresh dependency constraints for the expanded range.

Other Changes:

• Migrate the test runner to pytest and make the suite independent of the current working directory.
• Resolve Pyright errors, make the prompt base class generic, and enforce Pyright and Ruff checks in CI.
• Pin spaCy away from its broken 3.8.14 release and tighten the Numba constraint for clean installations.
• Run live LLM integration tests exclusively against the OpenAI-compatible deepseek-v4-flash model using DEEPSEEK_API_KEY locally and in GitHub Actions.