fix: constrain CI dependencies

[al-munazzim]

Summary

Fixes the current red CI dependency resolution without conflicting with Specter Desktop's pinned runtime environment.

• constrain Spectrum's runtime Flask requirement to <2.3 because Flask-SQLAlchemy==2.5.1 imports Flask internals removed in Flask 2.3+
• keep Werkzeug<3 as a test-only dependency, since Specter Desktop currently pins Werkzeug==3.0.3
• pin test-only bdkpython==0.32.1, because latest bdkpython==3.0.0 breaks tests/test_bdk.py

Fixes #63

Specter Desktop compatibility

Specter Desktop currently pins:

Flask==2.2.5
Werkzeug==3.0.3
cryptoadvance.spectrum==0.7.0

This PR keeps the runtime constraint compatible with Specter Desktop by only adding Flask<2.3 to Spectrum's runtime requirements. Werkzeug<3 is intentionally limited to Spectrum's [test] extra, so normal Specter Desktop installs are not forced away from their pinned Werkzeug==3.0.3.

Test plan

Fresh local venv on Python 3.11:

python -m pip install -e '/tmp/spectrum-review-62[test]'

Resolved key versions:

Flask 2.2.5
Werkzeug 2.3.8
Flask-SQLAlchemy 2.5.1
SQLAlchemy 1.4.54
bdkpython 0.32.1

Targeted tests:

pytest tests/test_util.py tests/test_se_healthz.py tests/test_bdk.py -q
3 passed, 18 warnings in 1.26s

Full suite:

pytest -q
17 passed, 1137 warnings in 18.19s