fix(notifications): filter SPS products by location zone

[Orinks]

Summary

• Filter office-wide Special Weather Statement products by the saved location's NWS zone IDs before notification evaluation.
• Parse UGC zone lines, including ranged forms such as TXZ105>107, and compare them with the location's forecast, fire, and county zone IDs.
• Add regression coverage for Copperas Cove (TXZ157) not receiving Dallas/Tarrant (TXZ118-119) SPS products while still keeping a local TXZ157 SPS.

Root cause

The active alert path honors the user's alert area setting, but the SPS product path reads the CWA-wide /products/types/SPS/locations/{office} cache. For offices like FWD, that feed includes Dallas-area statements even when a Copperas Cove point has no active alert. Without a zone filter, those office products could be treated as informational SPS notifications for the current location.

Validation

• uv run pytest -q -n 0 --tb=short tests/test_split_notification_timers.py::TestSpsProductLocationFiltering tests/test_notification_sps_dedupe.py
• latest Ruff: ruff format --check .
• uv run ruff check src tests
• uv run pyright