Add NY S.9077 Empire State Child Credit ITIN expansion reform

[DTrim99]

Summary

Implements structural reform for NY S.9077 which allows children with ITINs to qualify for the Empire State Child Credit starting in 2027.

Under current law (2025-2026), only children with SSNs qualify per federal CTC requirements (IRC 24(h)(7)). S.9077 Section D(V) explicitly includes ITIN holders:

"is a citizen or national of the United States, or an individual with an individual taxpayer identification number issued by the internal revenue service"

Changes

Parameters (gov/contrib/states/ny/s9077/)

• in_effect.yaml - Boolean to enable/disable reform (default: false)

Reform (reforms/states/ny/s9077/)

• ny_s9077_escc_itin.py - Reform that modifies ny_ctc_post_2024_base and ny_ctc_post_2024_eligible to allow ITIN holders when reform is active

Tests (tests/policy/contrib/states/ny/s9077/)

• Test cases for SSN children (baseline behavior)
• Test cases for ITIN children qualifying when reform active
• Test cases for ITIN children NOT qualifying when reform inactive
• Edge cases (no valid ID, mixed SSN/ITIN families, adult children)

Test plan

• All 8 reform tests pass
• Existing NY CTC tests unaffected

Closes #7286

References

• NY S.9077 - Empire State Child Credit Expansion