Calculate a traceable Bazi (Four Pillars/八字/四柱) chart from a Gregorian local birth date-time and IANA time zone, preserving traditional civil-time and modern topocentric apparent-Sun profiles. Use when a user asks to 排八字、排四柱、算生辰八字, calculate pillars, inspect Ten Gods, hidden stems, 纳音, 十二长生, 旺相休囚死, visible element counts, or obtain structured Bazi JSON. Also use before any Bazi interpretation when no validated chart exists.
