Add education credit eligibility inputs

[MaxGhenis]

Summary

• add lower-level American Opportunity Credit eligibility inputs for the statutory student, documentation, institution, identification, residency, improper-claim, and filing-status predicates
• compute is_eligible_for_american_opportunity_credit from those predicates instead of leaving it as an unpopulated input
• gate AOTC Form 1098-T/payee-statement, institution-EIN, and qualifying-SSN requirements with time-varying eligibility parameters
• add lower-level Lifetime Learning Credit predicates for eligible-institution attendance, Form 1098-T/exception, taxpayer/student identification, nonresident-alien disallowance, and MFS disallowance
• gate LLC qualified tuition through is_eligible_for_lifetime_learning_credit while continuing to exclude AOTC-eligible students from LLC expenses

Primary Sources

• 26 U.S.C. § 25A(b) for AOTC amount, refundability cross-reference, and eligible-student rules
• 26 U.S.C. § 25A(c) for the Lifetime Learning Credit amount
• 26 U.S.C. § 25A(f) for qualified tuition, eligible educational institutions, and the no-double-benefit rule between education credits
• 26 U.S.C. § 25A(g)(1) and 26 U.S.C. § 24(h)(7) for the post-2025 qualifying-SSN identification rule
• 26 U.S.C. § 25A(g)(7) for the nonresident-alien disallowance
• 26 U.S.C. § 25A(g)(8) for the Form 1098-T/payee-statement requirement
• 20 U.S.C. § 1091(a)(1), incorporated by 26 U.S.C. § 25A(b)(3)(A), for the recognized-credential enrollment rule

Tests

• uv run ruff format policyengine_us/variables/gov/irs/credits/education policyengine_us/tests/policy/baseline/gov/irs/credits/education/lifetime_learning_credit
• uv run ruff check policyengine_us/variables/gov/irs/credits/education policyengine_us/tests/policy/baseline/gov/irs/credits/education/lifetime_learning_credit
• uv run python -m policyengine_core.scripts.policyengine_command test policyengine_us/tests/policy/baseline/gov/irs/credits/education -c policyengine_us

Follow-up data PR: PolicyEngine/policyengine-us-data#843

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.53%. Comparing base (8675371) to head (ef9ae9b).
⚠️ Report is 103 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##              main    #8170      +/-   ##
===========================================
- Coverage   100.00%   95.53%   -4.47%     
===========================================
  Files            3       25      +22     
  Lines           39      291     +252     
  Branches         0        4       +4     
===========================================
+ Hits            39      278     +239     
- Misses           0       11      +11     
- Partials         0        2       +2     

Flag	Coverage Δ
unittests	95.53% <100.00%> (-4.47%)	⬇️

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.

[MaxGhenis]

Local paired build result using this PE-US branch with PolicyEngine/policyengine-us-data#843:

• Rebuilt PUF, Extended CPS half, and calibrated EnhancedCPS_2024 locally.
• Lifetime Learning Credit: $1.034B over 1.712M weighted positive tax units.
• Nonrefundable AOTC: $6.779B.
• Refundable AOTC: $5.166B over 5.615M weighted positive tax units.
• Full AOTC: $12.915B.
• Combined nonrefundable education credits: $7.813B over 7.161M weighted positive tax units.

Calibration log from the local build:

• Refundable AOTC target: $5.090B, estimate $5.071B, relative error -0.38%; count target 5.822M, estimate 5.544M, relative error -4.76%.
• Combined education-credit target: $7.555B, estimate $7.698B, relative error +1.90%; count target 7.211M, estimate 7.066M, relative error -2.02%.

There is no standalone LLC calibration target in this pair because IRS SOI Table 3.3 reports LLC only inside the combined nonrefundable education credit.