[codex] Add Kansas Lifeline supplement

[daphnehanse11]

Summary

• Adds the Kansas KCC Lifeline supplement parameter for the KUSF phone-service supplement.
• Adds ks_lifeline_supplement, capped by household phone costs.
• Integrates the supplement into the federal Lifeline calculation for KS households.

Closes #8579.

Validation

• uv run --extra dev ruff check policyengine_us/variables/gov/states/ks/kcc/lifeline/ks_lifeline_supplement.py policyengine_us/variables/gov/fcc/lifeline/lifeline.py
• uv run python -m policyengine_core.scripts.policyengine_command test policyengine_us/tests/policy/baseline/gov/states/ks/kcc/lifeline/ks_lifeline_supplement.yaml -c policyengine_us
• uv run python -m policyengine_core.scripts.policyengine_command test policyengine_us/tests/policy/baseline/gov/fcc/lifeline/lifeline.yaml -c policyengine_us

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (17cda0d) to head (3f58622).
⚠️ Report is 25 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##              main     #8586   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files            1         2    +1     
  Lines           19        40   +21     
  Branches         0         2    +2     
=========================================
+ Hits            19        40   +21     

Flag	Coverage Δ
unittests	100.00% <100.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.