Update the 2027 NC Special Assistance test case to the announced COLA

[hua7450]

What and why

nc_sa.yaml Case 37 has failed Full Suite - Baseline (states-shard-1) on main (release run 39281464293) and on every PR since #10225 merged. It is the only failing case in that job.

• Add North Carolina state supplementation for 2026 #10160 (merged October 16) wrote the case from the projected 2027 Social Security uprating index, 326.149 (2.8%).
• Update Social Security and SSI parameters for the 2027 COLA #10225 (merged October 19) recorded the actual 2027 index, 328.746 (SSA's 3.6% COLA), and the 2027 SSI federal benefit rate of $1,029.
• Update Social Security and SSI parameters for the 2027 COLA #10225's last CI run was on October 15, before Add North Carolina state supplementation for 2026 #10160 merged, and main does not require branches to be up to date. So neither PR's CI saw the other change.

This PR updates only the case's expected values; no model or parameter change.

Output	Before (projected)	After
nc_sa_rate	1,436	1,448 (1,397 × 328.746 / 317.265 = 1,447.55)
ssi	1,021.83	1,029 (announced 2027 FBR)
nc_sa	484	489 (1,448 + 70 − 1,029)

The model raises the rate by the unrounded CPI-W increase (3.62%). SSA's announced COLA is rounded to 3.6%, which would give $1,447. North Carolina's published 2027 rate replaces this projection, as the parameter notes; the case should be revisited then.

Test plan

• For policy changes: not applicable (expectation update for SSA's announced 2027 index and FBR; North Carolina has not published its 2027 rate).
• make format
• Changelog fragment in changelog.d/
• Full Suite - Baseline (states-shard-1) passes.

axiom: n/a: test expectation update only, no policy change

🤖 Generated with Claude Code

[MaxGhenis]

Thanks for unblocking main. One note for the follow-up, not a change request here: G.S. 108A-42.1(a) and (b) adjust both rates "using the federally approved Social Security cost-of-living adjustment effective for the applicable year" (statute). The approved 2027 COLA is 3.6% (SSA), so the 2027 rates are $1,397 × 1.036 = $1,447 (basic) and $1,792 × 1.036 = $1,857 (enhanced). The parameter's gov.ssa.uprating applies the unrounded CPI-W ratio (3.62%), which gives your $1,448.

Once this lands, a separate PR will add explicit 2027-01-01 values of 1,447 and 1,857 to rate/basic.yaml and rate/enhanced.yaml, citing the statute, and move Case 37 to 1,447 / 1,029 / 488.

[hua7450]

Thanks, agreed. I checked the statute and the rounded-COLA chain from the base rates reproduces both 2026 rates, so 1,447 and 1,857 are right for 2027. I'll do the follow-up once this merges.

[hua7450]

Closing: #10279 already landed the same Case 37 values (1,448 / 1,029 / 489). The statutory 2027 rates (1,447 basic, 1,857 enhanced) will come in a separate follow-up PR.