chore: update inference script and core logic for alignment

fix: ensure all reward values are strictly between 0 and 1

fix: ensure grader scores are strictly between 0 and 1 (not 0.0 or 1.0)

fix: full resubmission patch - fix [STEP] format, add close(), expose system_state, fix /state endpoint, improve reward variance

refactor: improve environment variable handling for API authentication - 18:47

fix(inference): lazily initialize OpenAI client to support test runner mocks

fix(inference): prioritize evaluator .env over default.env

fix(inference): exact match of OpenAI client init for AST validators

fix(inference): perfect alignment with pre-submission checklist defaults

Fix inference.py with proper error handling

initial clean push: N-A finalized build