bug fix for dynamic routing logic

chore: add structured logging across backend

chore: clean DB, enable static mount, update env for deploy

fix: interview turn limits, LLM fallback, and completion UI

updated ui, docs, tests

feat: add batch/topic/question DB queries

feat: add NeonDB schema (all tables) and apply_schema script

fix: auth quality issues — token cleanup, delete_cookie params, broad exception catch, dead import

feat: implement NeonDB SQL queries for users and refresh tokens

feat: implement asyncpg connection pool

chore: add backend directory structure and stub files