fix: correct GPT-5.2-Codex release date to December 18, 2025

[neubig]

Summary

Corrects the release date for GPT-5.2-Codex from 2025-12-11 to 2025-12-18.

Issue

The metadata file incorrectly listed the release date as December 11, 2025, which is when the GPT-5.2 base model was released. However, GPT-5.2-Codex (the coding-optimized variant) was released on December 18, 2025.

Source

OpenAI's official announcement confirms the December 18, 2025 release date:

• https://openai.com/index/introducing-gpt-5-2-codex/

Changes

• Updated results/GPT-5.2-Codex/metadata.json: release_date from 2025-12-11 → 2025-12-18

@neubig can click here to continue refining the PR

[github-actions]

📊 Progress Report

============================================================
OpenHands Index Results - Progress Report
============================================================

Target: Complete all model × benchmark pairs
  11 models × 5 benchmarks = 55 pairs
  (each pair requires all 3 metrics: score, cost_per_instance, average_runtime)

============================================================
OVERALL PROGRESS: ⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛ 100.0%
  Complete: 55 / 55 pairs
============================================================

✅ Schema Validation

============================================================
Schema Validation Report
============================================================

Results directory: /home/runner/work/openhands-index-results/openhands-index-results/results
Files validated: 28
  Passed: 28
  Failed: 0

============================================================
VALIDATION PASSED
============================================================

This report measures progress towards the 3D array goal (benchmarks × models × metrics) as described in #2.